Three-body breakup in deuteron-deuteron collisions at 160 MeV including quasifree scattering
I. Ciepal, G. Khatri, K. Bodek, A. Deltuva, N. Kalantar-Nayestanaki, S. Kistryn, B. Klos, A. Kozela, J. Kubos, P. Kulessa, A. Lobejko, A. Magiera, J. Messchendorp, I. Mazumdar, W. Parol, R. Ramazani-Sharifabadi, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, A. Wilczek, B. Wloch, A. Wronska, J. Zejma
abstract
A set of differential cross section of the three-body H-2(d, dp)n breakup reaction at 160-MeV deuteron beam energy is presented for 147 configurations covering a wide kinematical region around quasifree scattering. The experiment was performed at KVI in Groningen, the Netherlands, using the BINA detector. The cross-section data have been normalized to the H-2(d, d)H-2 elastic-scattering cross section. The data are compared to the results of recent single-scattering approximation (SSA) calculations for three-cluster breakup in deuteron-deuteron collisions. This comparison shows that SSA provides the correct order of magnitude of the cross sections. The studied energy is probably too low to meet the SSA assumptions which prevents better accuracy of the description.
Studies of Deuteron Breakup Reactions in Deuteron-Deuteron Collisions at 160MeV with BINA
I. Ciepal, K. Bodek, N. Kalantar-Nayestanaki, G. Khatri, S. Kistryn, B. Klos, A. Kozela, J. Kubos, P. Kulessa, A. Lobejko, A. Magiera, I. Mazumdar, J. Messchendorp, W. Parol, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, A. Wilczek, B. Wloch, A. Wronska, J. Zejma
abstract
A rich set of differential cross section of the three-body 2H(d,dp)n breakup reaction at 160MeV deuteron beam energy has been measured over a large range of the available phase space. The experiment was performed at KVI in Groningen, the Netherlands, using the BINA detector. The cross-section data for the breakup reaction have been normalized to the simultaneously measured 2H(d,d)2H elastic scattering cross section. The breakup cross sections obtained for 147 kinematically complete configurations near the quasi-free scattering kinematics are compared to the recent approximate calculations for the three-cluster breakup in deuteron-deuteron collisions. The cross sections for 294 kinematic configurations of the quasi-free scattering regime, for which no theoretical calculations exist, are also presented. Besides the three-body breakup, semi-inclusive energy distributions for the four-body 2H(d,pp)nn breakup are reported.
Investigation of the cross section for dd elastic scattering and dd -> n He-3 reactions at 160 MeV
I. Ciepal, J. Kubos, K. Bodek, N. Kalantar-Nayestanaki, G. Khatri, S. Kistryn, B. Klos, A. Kozela, P. Kulessa, A. Lobejko, A. Magiera, J. Messchendorp, I. Mazumdar, W. Parol, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, A. Wilczek, B. Wloch, A. Wronska, J. Zejma
abstract
Differential cross sections of H-2(d, d)H-2 elastic scattering and proton transfer H-2(d,He-3)n reactions at 160 MeV beam energy have been obtained. They have been normalized relative to the existing cross-section data for the H-2(d, d)H-2 elastic scattering at 180 and 130 MeV, benefitting from the negligible energy dependence of this observable at certain range of the four-momentum transfer. The experiment was performed at KVI in Groningen, the Netherlands, using the BINA detector. The elastic scattering data are compared to theoretical predictions based on the lowest-order term in the Neumann series expansion for four-nucleon transition operators. The calculations underpredict the data. The data presented in this paper can be used to validate the future theoretical findings.
Search for C violation in the decay eta -> pi(0)e(+)e(-) with WASA-at-COSY
R. Adlarson, WAC. Collaboration, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, A. Bondar, M. Buescher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, R. Fedorets, K. Foehl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Huesken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, A. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, R. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, R. Marciniewski, B. Marianski, HP. Morsch, R. Moskal, H. Ohm, W. Parol, EP. Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, et al.
abstract
We report on the search for the rare decay eta -> pi(0)e(+)e(-) which is of interest to study C violation in the electromagnetic interaction which would indicate contributions from physics beyond the Standard Model, since the allowed decay via a two-photon intermediate state is strongly suppressed. The experiment has been performed using the WASA-at-COSY installation, located at the COSY accelerator of the Forschungszentrum Julich, Germany. In total 3 x 10(7) events of the reaction pd -> He-3 eta have been recorded at an excess energy of Q = 59.8MeV. Based on this data set the C parity violating decay eta -> pi(0)gamma* -> pi(0)e(+)e(-) via a single-photon intermediate state has been searched for, resulting in new upper limits of Gamma(eta -> pi(0)e(+) e(-))/Gamma(eta -> pi(+) pi(-) pi(0)) < 3.28 x 10(-5) and Gamma(eta -> pi(0)e(+) e(-))/Gamma(eta -> all)< 7.5 x 10(-6) (CL=90%), respectively. (c) 2018 The Author. Published by Elsevier B.V.
Isotensor Dibaryon in the pp -> pp pi(+)pi(-) Reaction?
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, W. Parol, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, T. Skorodko, M. Skurzok, J. Smyrski, et al.
abstract
Exclusive measurements of the quasifree pp -> pp pi(+)pi(-) reaction have been carried out at WASA@ COSY by means of pd collisions at T-p = 1.2 GeV. Total and differential cross sections have been extracted covering the energy region T-p = 1.08-1.36 GeV, which is the region of N* (1440) and Delta(123)Delta(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor Delta N dibaryon resonance with I(J(P)) = 2(1(+)) produced associatedly with a pion is able to overcome these deficiencies.
Total and differential cross sections of eta-production in proton-deuteron fusion for excess energies between Q(eta)=13 MeV and Q(eta)=81 MeV
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erveno, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, A. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, W. Parol, EP. del Rio, NM. Piskunovu, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
New data on both total and differential cross sections of the production of eta mesons in proton-deuteron fusion to He-3 eta in the excess energy region 13.6 MeV <= Q(eta) <= 80.9 MeV are presented. These data have been obtained with the WASA-at-COSY detector setup located at the Forschungszentrum Julich, using a proton beam at 15 different beam momenta between p(p) = 1.60 GeV/c and p(p) = 1.74 GeV/c. While significant structure of the total cross section is observed in the energy region 20 MeV less than or similar to Q(eta) less than or similar to 60 MeV, a previously reported sharp variation around Q(eta) approximate to 50 MeV cannot be confirmed. Angular distributions show the typical forward- peaking that was noted earlier. For the first time, it is possible to study the development of these angular distributions with rising excess energy over a wide interval. (c) 2018 The Author. Published by Elsevier B.V.
Importance of d-wave contributions in the charge symmetry breaking reaction dd -> He-4 pi0
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, C. Hanhart, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, W. Parol, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
This letter reports a first quantitative analysis of the contribution of higher partial waves in the charge symmetry breaking reaction dd -> He-4 pi(0) using the WASA-at-COSY detector setup at an excess energy of Q = 60 MeV. The determined differential cross section can be parametrized as d sigma/d Omega = a + b cos(2) theta*, where theta* is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a = (1.55 +/- 0.46(stat)(-0.8)(+0.32)(syst)) pb/sr and b = (13.1 +/- 2.1(stat)(-2.7)(+1.0)(syst)) pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the A isobar to the dd -> He-4 pi(0) reaction and is, therefore, crucial for a quantitative understanding of quark mass effects in nuclear production reactions. (C) 2018 The Author(s). Published by Elsevier B.V.
Spin Dependence of eta Meson Production in Proton-Proton Collisions Close to Threshold
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, SD. Bass, FS. Bergmann, M. Berlowski, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, W. Parol, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high polarization degree of the proton beam of COSY, the reaction (p) over right arrowp -> pp eta has been measured close to threshold to explore the analyzing power A(y). The angular distribution of A(y) is determined with the precision improved by more than 1 order of magnitude with respect to previous results, allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q = 15 MeV, signaling s-wave production with no evidence for higher partial waves. At Q = 72 MeV the data reveal strong interference of Ps and Pp partial waves and cancellation of (Pp)(2) and Ss*Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the eta meson.
Non-equilibrium processes in p + Ag collisions at GeV energies
M. Fidelus,.., B. Kamys, S. Kistryn, A. Magiera, Z. Rudy, S. Sharma et al.,
abstract
The double differential spectra d2?/d?dE of p, d, t, He3,4,6, Li6,7,8,9, Be7,9,10, and B10,11,12 were measured at seven scattering angles, 15.6?, 20?, 35?, 50?, 65?, 80?, and 100?, in the laboratory system for proton induced reactions on a silver target. Measurements were done for three proton energies: 1.2, 1.9, and 2.5 GeV. The experimental data were compared to calculations performed by means of two-step theoretical microscopic models. The first step of the reaction was described by the intranuclear cascade model incl4.6 and the second one by four different models (ABLA07, GEM2, gemini++, and SMM) using their standard parameter settings. Systematic deviations of the data from predictions of the models were observed. The deviations were especially large for the forward scattering angles and for the kinetic energy of emitted particles in the range from about 50 to 150 MeV. This suggests that some important non-equilibrium mechanism is lacking in the present day microscopic models of proton-nucleus collisions in the studied beam energy range.
Non-equilibrium processes in p plus Ag collisions at GeV energies
M. Fidelus, D. Filges, F. Goldenbaum, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, E. Kozik, P. Kulessa, H. Machner, A. Magiera, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, SK. Sharma, R. Siudak, M. Wojciechowski
abstract
The double differential spectra d(2)sigma/d Omega dE of p, d, t, He-3,He-4,He-6, Li-6,Li-7,Li-8,Li-9, Be-7,Be-9,Be-10, and B-10,B-11,B-12 were measured at seven scattering angles, 15.6 degrees, 20 degrees, 35 degrees, 50 degrees, 65 degrees, 80 degrees, and 100 degrees, in the laboratory system for proton induced reactions on a silver target. Measurements were done for three proton energies: 1.2, 1.9, and 2.5 GeV. The experimental data were compared to calculations performed by means of two-step theoretical microscopic models. The first step of the reaction was described by the intranuclear cascade model INCL4.6 and the second one by four different models (ABLA07, GEM2, GEMINI++, and SMM) using their standard parameter settings. Systematic deviations of the data from predictions of the models were observed. The deviations were especially large for the forward scattering angles and for the kinetic energy of emitted particles in the range from about 50 to 150 MeV. This suggests that some important non-equilibrium mechanism is lacking in the present day microscopic models of proton-nucleus collisions in the studied beam energy range.
Isoscalar single-pion production in the region of Roper and d*(2380) resonances
P. Adlarsona, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, W. Parol, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
Exclusive measurements of the quasi-free pn -> pp pi(-) and pp -> pp pi(0) reactions have been performed by means of pd collisions at T-p= 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region T-p= 0.95-1.3 GeV (root s = 2.3-2.46 GeV), which includes the regions of triangle(1232), N*(1440) and d*(2380) resonance excitations. From these measurements the isoscalar single-pion production has been extracted, for which data existed so far only below T-p = 1 GeV. We observe a substantial increase of this cross section around 1 GeV, which can be related to the Roper resonance N*(1440), the strength of which shows up isolated from the triangle resonance in the isoscalar (N pi)(I=0) invariant-mass spectrum. No evidence for a decay of the dibaryon resonance d*(2380) into the isoscalar (NN pi)(I=0) channel is found. An upper limit of 180 mu b (90% CL.) corresponding to a branching ratio of 9% has been deduced. (c) 2017 The Author(s). Published by Elsevier B.V.
Measurement of the omega -> pi(+)pi(-)pi(0) Dalitz plot distribution The WASA-at-COSY Collaboration
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. RudyC, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
Using the production reactions pd -> He-3 omega and pp -> pp omega, the Dalitz plot distribution for the omega -> pi(+)pi(-)pi(0)decay is studied with the WASA detector at COSY, based on a combined data sample of (4.408 +/- 0.042) x 10(4) events. The Dalitz plot density is parametrised by a product of the P-wave phase space and a polynomial expansion in the normalised polar Dalitz plot variables Z and phi. For the first time, a deviation from pure P-wave phase space is observed with a significance of 4.1 sigma. The deviation is parametrised by a linear term 1+2 alpha Z, with alpha determined to be +0.147 +/- 0.036, consistent with the expectations of rho-meson-type final-state interactions of the P-wave pion pairs. (C) 2017 The Author. Published by Elsevier B.V.
PROBING THREE-AND FOUR-NUCLEON INTERACTIONS WITH THE DEUTERON BREAKUP REACTION
I. Ciepal, I. Skwira-Chalot, S. Kistryn, A. Kozela, A. Magiera, E. Stephan
abstract
Research in the domain of few-nucleon systems concerns reactions involving a small number of nucleons in which observables can be compared directly to exact computational methods - rigorous solutions of the Fad-deev equations. The investigations of such systems reveal existence of various dynamical ingredients such as the three-nucleon force, the Coulomb force or relativistic effects. A large set of the cross-section data of the H-1 (d, pp)n breakup reaction obtained at energy of 130 MeV was used to trace the Coulomb force effects. Comparisons of the cross-section data with the predictions using the realistic Argonne 18 potential are presented. The new set of invariants was introduced to describe the process with three nucleons in the final state.
Experimental Study of Three-Nucleon Dynamics in the Dp Breakup Collisions Using the WASA Detector
B. Klos, I. Ciepal, B. Jamroz, G. Khatri, S. Kistryn, A. Kozela, A. Magiera, W. Parol, I. Skwira-Chalot, E. Stephan
abstract
Until recently, all calculations of breakup observables were carried out in a non-relativistic regime. The relativistic treatment of the breakup reaction in 3N system is quite a new achievement. The detailed study of various aspects of few-nucleon system dynamics in medium energy region, with a particular emphasis on investigation of relativistic effects and their interplay with three nucleon force (3NF) becomes feasible with increasing available energy in the three nucleon system. Therefore an experiment to investigate the H-1(d, pp)n breakup cross section using a deuteron beam of 300, 340, 380 and 400 MeV and the WASA detector has been performed at COSY-Julich. The almost 4 pi geometry of the WASA detector gives an unique possibility to study variety of kinematic configurations, which reveal different sensitivity to aspects of dynamics of the three nucleon system. The main steps of the analysis, including energy calibration, PID, normalization and efficiency studies, and their impact on the final accuracy of the result, are discussed.
Search for eta-mesic He-4 in the dd -> (3)Hen pi(0) and dd -> (3)Hep pi(-) reactions with the WASA-at-COSY facility
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, E. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, NG. Kelkar, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magierae, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
The search for He-4-eta bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd -> (3)Hen pi(0) and dd -> (3)Hep pi(-) processes. The deuteron beam momentum was varied continuously between 2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the dd -> He-4 eta reaction ranging from Q = 70 MeV to Q = 30 MeV. The luminosity was determined based on the dd -> (3)Hen reaction and the quasi-free proton proton scattering via dd -> ppn(spectator)n(spectator) reactions. The excitation functions, determined independently for the measured reactions, do not reveal a structure which could be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the total cross sections for the bound state production and decay in dd -> (4He-eta)(bound) -> (3)Hen pi(0) and dd -> (He-4-eta)(bound) -> (3)Hep pi(-) processes were determined taking into account the isospin relation between the both of the considered channels. The results of the analysis depend on the assumptions of the N* (1535) momentum distribution in the anticipated mesic-He-4. Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in He-4, we determined that (for the mesic bound state width in the range from 5 MeV to 50 MeV) the upper limits at 90% confidence level are about 3 nb and about 6 nb for n pi(0) and p pi(-) channels, respectively. However, based on the recent theoretical findings of the N*(1535) momentum distribution in the N*-He-3 nucleus bound by 3.6 MeV, we find that the WASA-at-COSY detector acceptance decreases and hence the corresponding upper limits are 5 nb and 10 nb for n pi(0) and p pi(-) channels respectively. (C) 2017 Elsevier B.V. All rights reserved.
Measurements of branching ratios for eta decays into charged particles
P. AdlarsoN, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, G. Khatri, A. Khoukaz, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, H. Ohm, I. Ozerianska, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, et al.
abstract
The WASA-at-COSY experiment has collected 3 x 10(7) events with eta mesons produced via the reaction pd -> He-3 eta at T = 1.0 GeV. Using this data set, we evaluate the branching ratios of the decays eta -> pi(+)pi(-)gamma, eta -> e(+)e(-)gamma, eta -> pi(+)pi(-)e(+)e(-), and eta -> e(+)e(-)e(+)e(-). The branching ratios are normalized to the eta -> pi(+)pi(-) pi(0) decay. In addition an upper limit on a CP-violating asymmetry in eta -> pi(+)pi(-)e(+)e(-) is extracted.
Search for an isospin I=3 dibaryon
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, G. Khatri, A. Khoukaz, O. Khreptak, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, EP. del Rio, NM. Piskunov, D. Prasuhnl, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, et al.
abstract
Various theoretical calculations based on QCD or hadronic interactions predict that in addition to the recently observed dibaryon resonance d*(2380) with I(J(P)) = 3(0(+)) there should also exist a dibaryon resonance with mirrored quantum numbers I(J(P)) = 3(0(+)). We report here on a search for such a NN-decoupled state in data on the pp -> pp pi(+) pi(+) pi(-) pi(-) reaction. Since no clear-cut evidence has been found, we give upper limits for the production cross section of such a resonance in the mass range 2280-2500 MeV. (C) 2016 The Author(s). Published by Elsevier B.V.
Measurement of the (n)over-right-arrowp -> d pi(0) pi(0) reaction with polarized beam in the region of the d(*)(2380) resonance
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Caleen, I. Ciepa, H. Clement, E. Czerwinski, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Foohl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, V. Hejny, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, G. Khatri, A. Khoukaz, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, HP. Morsch, P. Moskal, H. Ohm, EP. del Rio, NM. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schatti-Ozerianska, T. Sefzick, V. Serdyuk, et al.
abstract
We report on a high-statistics measurement of the most basic double-pionic fusion reaction over the energy region of the d (*)(2380) resonance by use of a polarized deuteron beam and observing the double fusion reaction in the quasifree scattering mode. The measurements were performed with the WASA detector setup at COSY. The data reveal substantial analyzing powers and confirm conclusions about the d(*) resonance obtained from unpolarized measurements. We also confirm the previous unpolarized data obtained under complementary kinematic conditions.
DEUTERON-DEUTERON COLLISION AT 160 MeV
G. Khatri, W. Parol, K. Bodek, I. Ciepal, B. Jamroz, N. Kalantar-Nayestanaki, S. Kistryn, B. Klos, A. Kozela, P. Kulessa, A. Magiera, I. Mazumdar, JG. Messchendorp, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, A. Wilczek, B. Wloch, A. Wronska, J. Zejma
abstract
The experiment was carried out using BINA detector at KVI in Groningen. For the first time, an extensive analysis of the data collected in back part of the detector is presented, where a clusterization method is utilized for angular and energy information. We also present differential cross sections for the (dd -> dpn) breakup reaction within dp quasi-free scattering limit and their comparison with first calculations based on Single Scattering Approximation (SSA) approach.
Experimental study of Three-Nucleon Dynamics in the dp breakup reaction
B. Klos, I. Ciepal, G. Khatri, S. Kistryn, A. Kozela, A. Magiera, W. Paroi, I. Skwira-Chalot, E. Stephan, K. Szpik
abstract
An experiment to investigate the H-1(d,pp)n breakup reaction using a deuteron beam of 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY-Jtilich. The main goal was a detailed study of various aspects of few nucleon dynamics like the three nucleon force (3NF), the long-range Coulomb interaction or relativistic effects in the medium energy region. The relativistic effects and their interplay with 3NF become more important with increasing available energy in the three nucleon system. The almost 47r geometry of the WASA detector provides an unique possibility to study various aspects of dynamics. The studies of the 3N system dynamics in the breakup reaction with BINA detector are continued in the Cyclotron Center Bronowice.
Experimental study of three-nucleon dynamics in the dp breakup collisions using the WASA detector
B. Klos, I. Ciepal, G. Khatri, S. Kistryn, A. Kozela, A. Magiera, W. Parol, I. Skwira-Chalot, E. Stephan
abstract
An experiment to investigate the H-1(d, pp)n breakup reaction using a deuteron beam of 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY-Julich. The studied energy region, below but close to a pion production threshold, may provide information on various aspects of nuclear interactions, in particular on relativistic effects and their interplay with the three nucleon force (3NF). The almost 4 pi geometry of the WASA detector gives an unique possibility to study the different aspects of nucleon-nucleon dynamics in the three nucleon system. The main steps of the analysis, including energy calibration, PID and studied of efficiency, and their impact on final accuracy of the result, will be discussed.
Contribution of three nucleon force investigated in deuteron-proton breakup reaction
W. Parol, A. Kozela, I. Ciepal, K. Bodek, B. Jamroz, N. Kalantar-Nayestanaki, G. Khatri, S. Kistryn, B. Klos, J. Kubos, P. Kulessa, A. Magiera, I. Mazumdar, JG. Messchendorp, D. Rozpedzik, A. Rusnok, I. Skwira-Chalot, E. Stephan, A. Wilczek, B. Wloch, A. Wronska, J. Zejma
abstract
The elastic scattering and deuteron breakup data were collected in the experiment performed at KVI (Groningen) with use of unpolarized deuteron beam with energy of 80 MeV per nucleon, impinging on hydrogen target. The procedure applied to determine total integrated luminosity is presented. The result will be used for normalization of the differential cross section for the deuteron-proton breakup reaction.
Investigation of the Deuteron Breakup on Proton Target in the Forward Angular Region at 130 MeV
I. Ciepal, B. Klos, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, PU. Sauer, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witaa, J. Zejma
abstract
A set of differential cross-section data of the (1) H(d, pp)n breakup reaction at 130 MeV deuteron beam energy has been measured in the domain of very forward polar angles with the use of the Germanium Wall detector at the Forschungszentrum Julich. The data obtained for over 1000 kinematical points (112 geometries) are compared with the theoretical predictions based on various models of the three-nucleon (3N) dynamics. They comprise: the realistic nucleon-nucleon potentials alone or combined with the three-nucleon force (3NF), the coupled-channel calculations with the explicit treatment of the Delta-isobar excitation and finally, the potentials derived from chiral perturbation theory. In the part of the phase space studied, the Coulomb interaction between protons has a strong impact on the differential cross section of the breakup reaction. The strongest Coulomb effects are found in regions where the relative energy of the two protons is the smallest. In these regions the data are well reproduced exclusively by calculations which include the electromagnetic repulsion between protons. In spite of the dominance of the Coulomb force in the phase space studied, the contribution of 3NF effects is also observed.
Experimental Investigation of Few-Nucleon Dynamics at Medium Energies
G. Khatri, K. Bodek, I. Ciepal, N. Kalantar-Nayestanaki, S. Kistryn, B. Klos, A. Kozela, A. Magiera, I. Mazumdar, JG. Messchendorp, W. Parol, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, A. Wronska, J. Zejma
abstract
An experiment, with unpolarized deuteron beam of 160 MeV impinging on liquid hydrogen and liquid deuterium targets, was carried out using BINA detector at KVI, in Groningen, the Netherlands. Data were collected for the purpose of obtaining high precision differential cross-section for the deuteron break-up reaction. The elastic scattering data were also collected alongside. We present here the methods applied in analysis of data collected in the backward part of the detector.
Measurement of the np -> np pi(0)pi(0) reaction in search for the recently observed d* (2380) resonance
P. Adlarsona, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, B. Hoistad, N. Husken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, H. Ohm, I. Ozerianska, EP. del Rio, NM. Piskunov, P. Podkopal, D. Prasuhn, A. Pricking, D. Pszczel, K. Pysz, et al.
abstract
Exclusive measurements of the quasi-free np --> np pi(0)pi(0) reaction have been performed by means of dp collisions at T-d = 2.27 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region root s = (2.35-2.46) GeV, which includes the region of the ABC effect and its associated d* (2380) resonance. Adding the d* resonance amplitude to that for the conventional processes leads to a reasonable description of the data. The observed resonance effect in the total cross section is in agreement with the predictions of Faldt and Wilkin as well with those of Albadajedo and Oset. The ABC effect, i.e. the low-mass enhancement in the pi(0)pi(0)-invariant mass spectrum, is found to be very modest - if present at all, which might pose a problem to some of its interpretations. (C) 2015 The Authors. Published by Elsevier B.V.
COULOMB FORCE EFFECTS IN DEUTERON-PROTON BREAKUP REACTION
I. Ciepal, B. Klos, A. Kozela, E. Stephan, S. Kistryn, A. Biegun, K. Bodek, A. Deltuva, M. Eslami-Kalantari, V. Jha, N. Kalantar-Nayestanaki, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, M. Kravcikova, P. Kulessa, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, I. Skwira-Chalot, R. Sworst, J. Urban, J. Zejma
abstract
A large set of cross-section data for the H-1 (d,pp)n breakup reaction was measured at 130 MeV deuteron beam energy with the Germanium Wall setup covering the range of very forward polar angles. In the investigated part of the phase-space, the dynamics is dominated by the Coulomb force influence. The data are compared with results of theoretical calculations based on the realistic Argonne V18 potential supplemented with the long-range electromagnetic component. The predictions also include the Urbana IX three nucleon force model. The cross-section data reveal seizable Coulomb force effects.
Measurement of the eta -> pi(+)pi(-)pi(0) Dalitz plot distribution
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, M. Hodana, B. Hoistad, N. Husken, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, DA. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, BV. Martemyanov, UG. Meissner, M. Mikirtychiants, HP. Morsch, P. Moskal, H. Ohm, I. Ozerianska, EP. del Rio, NM. Piskunov, et al.
abstract
The Dalitz plot distribution of the eta -> pi(+)pi(-)pi(0) decay is determined by using a data sample of 1.2 x 10(7) eta mesons from the pd -> He-3 eta reaction at 1 GeV collected by the WASA detector at COSY.
The 22nd European Conference on Few-Body Problems in Physics, Krakow 2013 Preface
J. Golak, S. Kistryn, R. Skibiński
abstract
Investigation of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction
I. Ciepal, B. Klos, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witała, J. Zejma
abstract
Precise and large sets of cross section, vector A (x) , A (y) and tensor A (xx) , A (xy) , A (yy) analyzing power data for the (1) H(d, pp)n breakup reactions were measured at 100 and 130 MeV deuteron beam energies with the SALAD and BINA detectors at KVI and the Germanium Wall setup at FZ-Julich. Results are compared with various theoretical approaches which model the three-nucleon system dynamics. The cross section data reveal a sizable three-nucleon force (3NF) and Coulomb force influence. In case of the analyzing powers very low sensitivity to these effects was found and the data are well describe by 2N models only. For A (xy) at 130 MeV, serious disagreements were observed when 3NF models are included in the calculations.
Systematic Study of Three-Nucleon Systems Dynamics in the Cross Section of the Deuteron-Proton Breakup Reaction
B. Klos, I. Ciepal, B. Jamroz, G. Khatri, S. Kistryn, A. Kozela, A. Magiera, W. Parol, I. Skwira-Chalot, E. Stephan
abstract
An experiment to investigate the H-1(d, pp)n breakup reaction using a deuteron beam of 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY-Julich. The main goal was the detailed study of various aspects of few-nucleon dynamics in the medium energy region, with particular emphasis on relativistic effects and their interplay with three nucleon forces. These effects become more important with increasing available energy in the three nucleon system. Therefore the investigations at high energies are crucial to understand their nature. The almost 4 pi geometry of the WASA detector gives an unique possibility to study various aspects of dynamics of processes in the three-nucleon reaction. Preliminary results obtained using the WASA detector are presented.
Few-Nucleon System Dynamics Studied via Deuteron-Deuteron Breakup Reactions at 160 MeV
G. Khatri, I. Ciepal, K. Bodek, N. Kalantar-Nayestanaki, S. Kistryn, B. Klos, A. Kozela, A. Magiera, I. Mazumdar, J. Messchendorp, W. Parol, I. Skwira-Chalot, E. Stephan, D. Rozpedzik, A. Wronska, J. Zejma
abstract
An experiment, with the deuteron beams at energy of 160 MeV impinging on the liquid deuterium target, was carried out using the BINA detector at KVI, in Groningen, the Netherlands. Data were collected for the purpose of obtaining high precision differential cross-sections for the deuteron break-up reaction. The elastic scattering channel was also measured alongside for the purpose of cross-section normalization.
Sequential and simultaneous emission of particles from p plus Al collisions at GeV energies
M. Fidelus, D. Filges, F. Goldenbaum, H. Hodde, A. Jany, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, S. Kliczewski, E. Kozik, P. Kulessa, H. Machner, A. Magiera, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, SK. Sharma, R. Siudak, M. Wojciechowski
abstract
The energy and angular dependence of double differential cross sections d(2)sigma/d Omega dE were measured for p, d, t, He-3,He-4,He-6, Li-6,Li-7,Li-8,Li-9, Be-7,Be-9,Be-10, and B-10,B-11 produced in collisions of 1.2, 1.9, and 2.5 GeV protons with an Al target. It was found that the cross sections are almost independent of the beam energy. The spectra and angular distributions indicate a presence of two contributions: a quasi-isotropic, low-energy one which is attributed to the emission of particles from excited remnants of the intranuclear cascade, and an anisotropic part which is interpreted to originate from the first stage of the reaction. The experimental data are compared with an intranuclear cascade model coupled to evaporation, and to statistical multifragmentation models using their standard parameter settings. It was found that all applied models produce very similar results describing spectra of the intermediate mass fragments. All models also reproduce well the low-energy part of the spectra of light charged particles (below approximate to 30 MeV). The description of the higher energy part (50-150 MeV) of the light charged particles spectra is poorer, deteriorating with decreasing scattering angle and decreasing mass of the particles.
Investigation of three nucleon force effects in deuteron-proton breakup reaction
W. Parol, I. Ciepal, K. Bodek, S. Kistryn, G. Khatri, A. Magiera, D. Rozpedzik, A. Wronska, J. Zejma, B. Klos, E. Stephan, A. Kozela, P. Kulessa, N. Kalantar-Nayestanaki, J. Messchendorp, I. Mazumdar, I. Skwira-Chalot
abstract
Experiments devoted to study subtle ingredients of nuclear dynamics were carried out at KVI in Groningen with the use of the H-1(d,pp)n breakup reaction at the deuteron beam energy of 80 MeV/nucleon. The aim of the work is to determine the breakup cross sections and confront them with the set of modern calculations which model forces acting between nucleons. Elastic scattering process was also measured for the purpose of the cross section normalization. This paper presents preliminary results of the data analysis including geometry cross check, energy calibration, particles identification and sample distributions of the unnormalized breakup cross sections.
Investigation of three nucleon force effects in deuteron-proton breakup reaction India
W. Parol, A. Kozela, I. Ciepal, B. Klos, K. Bodek, J. Golak, N. Kalantar-Nayestanaki, G. Khatri, S. Kistryn, P. Kulessa, A. Magiera, I. Mazumdar, J. Messchendorp, D. Rozpedzik, R. Skibiński, I. Skwira-Chalot, E. Stephan, H. Witała, A. Wronska, J. Zejma
abstract
Experimental study of the deuteron-proton breakup process was perfomed in KVI Groningen. In this paper current status of the collected data analysis is presented, including preliminary results of the cross section for the sample kinematical configuration.
Studies of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction
I. Ciepal, B. Klos, E. Stephan, S. Kistryn, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibinski, R. Sworst, J. Urban, H. Witala, J. Zejma
abstract
One of the most important goals of modern nuclear physics is to contruct nuclear force model which properly describes the experimental data. To develop and test predictions of current models the breakup 1H(d(->), pp)n reaction was investigated experimentally at 100 and 130 MeV deuteron beam energies. Rich set of data for cross section, vector and tensor analyzing powers was obtained with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Julich. Results are compared with various theoretical approaches which describe the three-nucleon (3N) system dynamics. For correct description of the cross section data both, three-nucleon force (3NF) and Coulomb force, have to be included into calculations and influence of those ingredients is seizable at specific parts of the phase space. In case of the vector analyzing powers very low sensitivity to any effects beyond nucleon-nucleon interaction was found. At 130 MeV, the A(xy) data are not correctly described when 3NF models are included into calculations.
Experimental study of relativistic effects in the dp breakup reaction using the WASA detector
B. Klos, I. Ciepal, B. Jamroz, G. Khatri, S. Kistryn, A. Kozela, A. Magiera, W. Parol, I. Skwira-Chalot, E. Stephan
abstract
An experiment to investigate the H-1((sic) pp)n breakup reaction at 340 MeV, 360 MeV and 400 MeV deuteron beam energy has been performed at the Cooler Synchrotron COSY-Julich with the WASA detecr. The main goal was to study of various aspects of few-nucleon dynamics in the medium energy region, with a particular emphasis on relativistic effects and their interplay with three nucelon forces. The almost 4 pi geometry of the WASA detector gives an unique possibility to study the different aspects of nucleon-nucleon dynamics in the three nucleon system. The preliminary analysis of the collected data is presented.
Experimental Investigation of the Few-Nucleon Dynamics in Deuteron-Deuteron Collision at 160 MeV
G. Khatri, K. Bodek, I. Ciepal, N. Kalantar-Nayestanaki, S. Kistryn, B. Klos, A. Kozela, A. Magiera, I. Mazumdar, J. Messchendorp, W. Parol, D. Rozpedzik, I. Skwira-Chalot, E. Stephan, A. Wronska, J. Zejma
abstract
An experiment, with unpolarized deuteron beam of 160 MeV impinging on liquid deuterium target, was carried out using BINA detector at KVI, in Groningen, the Netherlands. Data were collected for the purpose of obtaining high precision differential cross-section for the deuteron break-up reaction. The elastic scattering data were also collected alongside for the purpose of cross-section normalization. We present here a sample of the un-normalised cross-section for the three-body final state (dd -> dpn) reaction.
Investigation of three nucleon force effects in deuteron-proton breakup reaction India
W. Parol, A. Kozela, I. Ciepal, B. Klos, K. Bodek, J. Golak, N. Kalantar-Nayestanaki, G. Khatri, S. Kistryn, P. Kulessa, A. Magiera, I. Mazumdar, J. Messchendorp, D. Rozpedzik, R. Skibinski, I. Skwira-Chalot, E. Stephan, H. Witala, A. Wronska, J. Zejma
abstract
Experimental study of the deuteron-proton breakup process was perfomed in KVI Groningen. In this paper current status of the collected data analysis is presented, including preliminary results of the cross section for the sample kinematical configuration.
Studies of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction
I. Ciepal, B. Klos, E. Stephan, S. Kistryn, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witała, J. Zejma
abstract
One of the most important goals of modern nuclear physics is to contruct nuclear force model which properly describes the experimental data. To develop and test predictions of current models the breakup 1H(d(->), pp)n reaction was investigated experimentally at 100 and 130 MeV deuteron beam energies. Rich set of data for cross section, vector and tensor analyzing powers was obtained with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Julich. Results are compared with various theoretical approaches which describe the three-nucleon (3N) system dynamics. For correct description of the cross section data both, three-nucleon force (3NF) and Coulomb force, have to be included into calculations and influence of those ingredients is seizable at specific parts of the phase space. In case of the vector analyzing powers very low sensitivity to any effects beyond nucleon-nucleon interaction was found. At 130 MeV, the A(xy) data are not correctly described when 3NF models are included into calculations.
Measurement of the pn -> pp pi(0)pi(-) reaction in search for the recently observed resonance structure in d pi(0)pi(0) and d pi(+)pi(-) systems
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, DA. Kirillov, S. Kistryn, J. Klaja, H. Kleines, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, H. Ohm, I. Ozerianska, EP. del Rio, NM. Piskunov, P. Plucinski, P. Podkopal, et al.
abstract
Exclusive measurements of the quasifree pn -> pp pi(0)pi(-) reaction have been performed by means of pd collisions at T-p = 1.2 GeV using the wide angle shower apparatus (WASA) detector setup at the cooler synchrotron COSY (Institut fur Kernphysik, Julich). Total and differential cross sections have been obtained covering the energy region root s = (2.35-2.46) GeV, which includes the region of the ABC effect and its associated resonance structure. NoABCeffect, i.e., low-mass enhancement is found in the pi(0)pi(-) -invariant mass spectrum, in agreement with the constraint from Bose statistics that the isovector pion pair can not be in relative s wave. At the upper end of the covered energy region t-channel processes for Roper, Delta(1600) and Delta Delta excitations provide a reasonable description of the data, but at low energies the measured cross sections are much larger than predicted by such processes. Adding a resonance amplitude for the resonance at m = 2.37 GeV with Gamma = 70 MeV and I (J(P)) = 0(3(+)) observed recently in pn -> d pi(0)pi(0) and pn -> d pi(+)pi(-) reactions leads to an agreement with the data also at low energies.
Search for a dark photon in the pi(0) -> e(+)e(-)gamma decay
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, E. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauensteinn, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, DA. Kirillov, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, UG. Meissner, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, H. Ohm, I. Ozerianska, EP. del Rio, et al.
abstract
The presently world largest data sample for pi(0) -> gamma e(+)e(-) decays studies containing nearly 5 x 10(5) events was collected using the WASA detector at COSY. A search for a dark photon U produced in the pi(0) -> gamma U -> gamma e(+)e(-) decay from the pp -> pp pi(0) reaction was carried out. An upper limit on the square of the U -> gamma mixing strength parameter epsilon(2) of 5 x 10(-6) at 90% CL was obtained for the mass range 20 MeV < M-U < 100 MeV. This result together with other recent experimental limits significantly reduces the M-U vs. epsilon(2) parameter space which could explain the presently seen deviation between the Standard Model prediction and the direct measurement of the anomalous magnetic moment of the muon. (C) 2013 Elsevier B.V. All rights reserved.
Investigations of Few-Nucleon System Dynamics in Medium Energy Domain
I. Ciepal, B. Klos, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witała, A. Wronska, J. Zejma
abstract
Precise and large set of cross sections, vector A (x) , A (y) and tensor A (xx) , A (xy) , A (yy) analyzing powers for the (1) H(d, pp)n breakup reactions were measured at 100 and 130 MeV deuteron beam energies with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Julich. Results are compared with various theoretical approaches which model the three-nucleon (3N) system dynamics. The calculations are based on different two-nucleon (2N) potentials which can be combined with models of the three-nucleon force (3NF) and other pieces of the dynamics can also be included like the Coulomb interaction and relativistic effects. The cross sections data reveal seizable 3NF and Coulomb force influence. In case of analyzing powers very low sensitivity to the effects was found and the data are well describe by 2N models only. At 130 MeV for A (xy) serious disagreements appear when 3NF models are included into calculations.
Investigation of the dd -> (3)Hen pi(0) reaction with the FZ Julich WASA-at-COSY facility
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, FS. Bergmann, M. Berlowski, H. Bhatt, M. Buscher, H. Calen, I. Ciepal, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, C. Hanhart, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, DA. Kirillov, S. Kistryn, J. Klaja, H. Kleines, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, H. Ohm, I. Ozerianska, EP. del Rio, NM. Piskunov, P. Plucinski, et al.
abstract
An exclusive measurement of the dd -> (3)Hen pi(0) reaction was carried out at a beam momentum of p(d) = 1.2 GeV/c using the WASA-at-COSY facility. Information on the total cross section as well as differential distributions was obtained. The data are described by a phenomenological approach based on a combination of a quasifree model and a partial wave expansion for the three-body reaction. The total cross section is found to be sigma(tot) = ( 2.89 +/- 0.01(stat) +/- 0.06(sys) +/- 0.29(norm)) mu b. The contribution of the quasifree processes ( with the beam or target neutron being a spectator) accounts for 38% of the total cross section and dominates the differential distributions in specific regions of phase space. The remaining part of the cross section can be described by a partial wave decomposition indicating the significance of p-wave contributions in the final state.
Isospin decomposition of the basic double-pionic fusion in the region of the ABC effect
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, I. Ozerianska, EP. del Rio, P. Plucinski, P. Podkopal, et al.
abstract
Exclusive and kinematically complete high-statistics measurements of the basic double-pionic fusion reactions pn -> d pi(0)pi(0), pn -> d pi(+)pi(-) and pp -> d pi(+)pi(0) have been carried out simultaneously over the energy region of the ABC effect using the WASA detector setup at COSY. Whereas the isoscalar reaction part given by the d pi(0)pi(0) channel exhibits the ABC effect, i.e. a low-mass enhancement in the pi pi-invariant mass distribution, as well as the associated resonance structure in the total cross section, the isovector part given by the d pi(+)pi(0) channel shows a smooth behavior consistent with the conventional t-channel Delta Delta process. The d pi(+)pi(-) data are very well reproduced by combining the data for isovector and isoscalar contributions, if the kinematical consequences of the isospin violation due to different masses for charged and neutral pions are taken into account. (C) 2013 Elsevier B.V. All rights reserved.
SYSTEMATIC STUDIES OF THE THREE-NUCLEON SYSTEM DYNAMICS IN THE DEUTRON-PROTON BREAKUP REACTION
B. Klos, I. Ciepal, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, B. Jamroz, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibinski, R. Sworst, J. Urban, H. Witala, A. Wronska, J. Zejma
abstract
Precise and large sets of data for cross section, vector and tensor analyzing powers for the H-1((d) over right arrow ,pp)n breakup reaction were obtained in experiments carried out at KVI Groningen and FZ-Julich at deuteron beam energies of 100 MeV, 13 MeV and 160 MeV (cross sections only). These precise experimental data obtained in a wide phase-space region allowed to establish evidences for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force. The vector analyzing powers data are generally quite well described by theoretical predictions even with pure nucleon nucleon interactions. Tensor analyzing powers can be also very well reproduced by calculations in most of the studied region but in some regions locally discrepancies are observed at energy of 130 MeV. DOI:10.5506/APhysPolB.44.345
SYSTEMATIC STUDIES OF THE THREE-NUCLEON SYSTEM DYNAMICS IN THE DEUTRON-PROTON BREAKUP REACTION
B. Klos, I. Ciepal, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, B. Jamroz, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witała, A. Wronska, J. Zejma
abstract
Precise and large sets of data for cross section, vector and tensor analyzing powers for the H-1((d) over right arrow ,pp)n breakup reaction were obtained in experiments carried out at KVI Groningen and FZ-Julich at deuteron beam energies of 100 MeV, 13 MeV and 160 MeV (cross sections only). These precise experimental data obtained in a wide phase-space region allowed to establish evidences for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force. The vector analyzing powers data are generally quite well described by theoretical predictions even with pure nucleon nucleon interactions. Tensor analyzing powers can be also very well reproduced by calculations in most of the studied region but in some regions locally discrepancies are observed at energy of 130 MeV. DOI:10.5506/APhysPolB.44.345
Vector analyzing powers of the deuteron-proton elastic scattering and breakup at 100 MeV
E. Stephan, S. Kistryn, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, M. Eslami-Kalantari, AC. Fonseca, I. Gasparic, J. Golak, L. Joulaeizadeh, N. Kalantar-Nayestanaki, H. Kamada, B. Klos, A. Kozela, JG. Messchendorp, H. Moeini, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, R. Skibiński, R. Sworst, A. Wilczek, H. Witała, J. Zejma
abstract
High-quality vector analyzing power data for the H-1(d,pp)n breakup reaction and elastic scattering at 100 MeV beam energy have been measured in a large part of the phase space for these processes. The results are compared to theoretical predictions obtained using the charge-dependent Bonn potential alone or combined with the three-nucleon force TM99 as well as to the results of calculations in the coupled-channel approach, with or without the inclusion of the Coulomb interaction. In the studied observables, effects of the 3NF and the Coulomb force are almost absent. The pairwise NN interactions alone are sufficient to describe the experimental results.
Search for the eta-mesic 4He with WASA-at-COSY detector
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, M. Krapp, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, I. Ozerianska, EP. del Rio, P. Plucinski, P. Podkopal, et al.
abstract
An exclusive measurement of the excitation function for the dd->3Heppi- reaction was performed at the Cooler Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were taken during a slow acceleration of the beam from 2.185 GeV/c to 2.400 GeV/c crossing the kinematic threshold for the eta meson production in the dd->4He-eta reaction at 2.336 GeV/c. The corresponding excess energy with respect to the 4He-eta system varied from -51.4MeV to 22MeV. The integrated luminosity in the experiment was determined using the dd->3Hen reaction. The shape of the excitation function for the dd->3Heppi- was examined. No signal of the 4He-eta bound state was observed. An upper limit for the cross-section for the bound state formation and decay in the process dd->(4He-eta)bound->3Heppi- was determined on the 90% confidence level and it varies from 20nb to 27nb for the bound state width ranging from 5MeV to 35MeV, respectively.
Abashian-Booth-Crowe resonance structure in the double pionic fusion to He-4
P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, CO. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, C. Husmann, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, FA. Khan, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, I. Ozerianska, C. Pauly, EP. del Rio, Y. Petukhov, et al.
abstract
Exclusive and kinematically complete high-statistics measurements of the double pionic fusion reaction dd?4He?0?0 have been performed in the energy range 0.8?1.4 GeV covering thus the region of the Abashian-Booth-Crowe effect, which denotes a pronounced low-mass enhancement in the ?? invariant mass spectrum. The experiments were carried out with the WASA detector setup at the cooler synchrotron at Forshungszentrum Julich GmbH. Similar to the observation in the basic pn?d?0?0 reaction, the data reveal a correlation between the ABC effect and a resonancelike energy dependence in the total cross section. The maximum occurs at m=2.37 GeV + 2mN, i.e., at the same position as in the basic reaction. The observed resonance width ??160 MeV can be understood from broadening due to Fermi motion of the nucleons in initial and final nuclei together with collision damping. Differential cross sections are described equally well by the hypothesis of a pn resonance formation during the reaction process.
Technical Design Report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
W. Erni, ..., S. Jowzaee, M. Kajetanowicz, B. Kamys, S. Kistryn, G. Korcyl, K. Korcyl, W. Krzemień, A. Magiera, P. Moskal, M. Palka, Z. Rudy, P. Salabura, J. Smyrski, A. Wrońska et al.
abstract
This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM-stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy-loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole Panda scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
Exclusive measurement of the eta->pi+ pi- gamma decay
P. Adlarson, C. Adolph, W. Augustyniak, W. Bardan, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, CO. Gullstrom, C. Hanhart, L. Heijkenskjold, J. Heimlich, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, M. Jacewicz, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, O. Khakimova, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, F. Kren, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, S. Leupold, B. Lorentz, A. Magiera, R. Maier, B. Marianski, P. Marciniewski, UG. Meissner, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, A. Passfeld, C. Pauly, et al.
abstract
An exclusive measurement of the decay eta --> pi+ pi- gamma has been performed at the WASA facility at COSY. The eta mesons were produced in the fusion reaction pd --> 3He X at a proton beam momentum of 1.7 GeV/c. Efficiency corrected differential distributions have been extracted based on 13340pm140 events after background subtraction. The measured pion angular distribution is consistent with a relative p-wave of the two-pion system, whereas the measured photon energy spectrum was found at variance with the simplest gauge invariant matrix element of eta --> pi+ pi- gamma. A parameterization of the data can be achieved by the additional inclusion of the empirical pion vector form factor multiplied by a first-order polynomial in the squared invariant mass of the pi+ pi- system.
pi0 pi0 Production in proton-proton collisions at Tp=1.4 GeV
P. Adlarson, C. Adolph, W. Augustyniak, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, CO. Gullstrom, L. Heijkenskjold, J. Heimlich, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, M. Jacewicz, M. Janusz, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, O. Khakimova, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, F. Kren, W. Krzemien, P. Kulessa, A. Kupsc, K. Lalwani, B. Lorentz, A. Magiera, R. Maier, B. Marianski, P. Marciniewski, M. Mikirtychiants, HP. Morsch, P. Moskal, BK. Nandi, S. Niedzwiecki, H. Ohm, A. Passfeld, C. Pauly, EP. del Rio, Y. Petukhov, N. Piskunov, et al.
abstract
The reaction pp->pppi0pi0 has been investigated at a beam energy of 1.4 GeV using the WASA-at-COSY facility. The total cross section is found to be (324 +- 21_systematic +- 58_normalization) mub. In order to to study the production mechanism, differential kinematical distributions have been evaluated. The differential distributions indicate that both initial state protons are excited into intermediate Delta(1232) resonances, each decaying into a proton and a single pion, thereby producing the pion pair in the final state. No significant contribution of the Roper resonance N*(1440) via its decay into a proton and two pions is found
Studies of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction
I. Ciepal, B. Klos, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibinski, R. Sworst, J. Urban, H. Witala, A. Wronska, J. Zejma
abstract
Precise and large sets of cross sections for the H-1(d,pp)n and H-2(p,pp)n breakup reactions were measured at 130 deuteron and 190 MeV proton beam energies with the use of detectors which covered almost the full phase space. The results are compared with various theoretical approaches which model the 3N system dynamics. The calculations are based on different 2N potentials which can be combined with models of the three-nucleon force (3NF). The differential cross sections appear to be a very sensitive tool for testing the interaction models and allow to search for various ingredients of the dynamics, not only the 3NF but also the Coulomb interaction and relativistic effects which are relatively new achievements of the theory.
Studies of the Three-Nucleon System Dynamics in the Deuteron-Proton Breakup Reaction
I. Ciepal, B. Klos, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, J. Golak, V. Jha, N. Kalantar-Nayestanaki, H. Kamada, G. Khatri, D. Kirillov, D. Kirillov, S. Kliczewski, A. Kozela, M. Kravcikova, H. Machner, A. Magiera, G. Martinska, J. Messchendorp, A. Nogga, W. Parol, A. Ramazani-Moghaddam-Arani, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witała, A. Wronska, J. Zejma
abstract
Precise and large sets of cross sections for the H-1(d,pp)n and H-2(p,pp)n breakup reactions were measured at 130 deuteron and 190 MeV proton beam energies with the use of detectors which covered almost the full phase space. The results are compared with various theoretical approaches which model the 3N system dynamics. The calculations are based on different 2N potentials which can be combined with models of the three-nucleon force (3NF). The differential cross sections appear to be a very sensitive tool for testing the interaction models and allow to search for various ingredients of the dynamics, not only the 3NF but also the Coulomb interaction and relativistic effects which are relatively new achievements of the theory.
Abashian-Booth-Crowe effect in basic double fusion: A new resonance?
P. Adlarson, C. Adolph, W. Augustyniak, V. Baru, M. Bashkanov, T. Bednarski, FS. Bergmann, M. Berlowski, H. Bhatt, KT. Brinkmann, M. Buscher, H. Calen, H. Clement, D. Coderre, E. Czerwinski, E. Doroshkevich, C. Ekstrom, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Fohl, K. Fransson, F. Goldenbaum, P. Goslawski, K. Grigoryev, V. Grishina, CO. Gullstrom, J. Hampe, C. Hanhart, L. Heijkenskjold, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, M. Jacewicz, M. Janusz, A. Jany, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, O. Khakimova, A. Khoukaz, S. Kistryn, J. Klaja, H. Kleines, B. Klos, F. Kren, W. Krzemien, P. Kulessa, S. Kullander, A. Kupsc, K. Lalwani, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Marianski, M. Mikirtychiants, P. Moskal, HP. Morsch, BK. Nandi, S. Niedzwiecki, H. Ohm, et al.
abstract
We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn->dpi0pi0 over the full energy region of the ABC effect, a pronounced low-mass enhancement in the pipi-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t-channel DeltaDelta process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m=2.37??GeV, Gamma aprox 70 MeV and I(JP)=0(3+) in both pn and DeltaDelta systems. Necessary further tests of the resonance interpretation are discussed.
Vector and Tensor Analyzing Powers in Deuteron-Proton Breakup
E. Stephan, S. Kistryn, N. Kalantar-Nayestanaki, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, M. Eslami-Kalantari, AC. Fonseca, I. Gasparic, J. Golak, B. Jamroz, L. Joulaeizadeh, H. Kamada, M. Kis, B. Klos, A. Kozela, M. Mahjour-Shafiei, H. Mardanpour, J. Messchendorp, A. Micherdzinska, H. Moeini, A. Nogga, A. Ramazani-Moghaddam-Arani, R. Skibiński, R. Sworst, H. Witała, J. Zejma
abstract
High precision data for vector and tensor analyzing powers of the (1)H (d(->), pp)nbreakup reaction at 130 and 100 MeV deuteron beam energies have been measured in a large fraction of the phase space. They are compared to the theoretical predictions based on various approaches to describe the three nucleon (3N) system dynamics. Theoretical predictions describe very well the vector analyzing power data, with no need to include any three-nucleon force effects for these observables. Tensor analyzing powers can be also very well reproduced by calculations in most of the studied region, but locally certain discrepancies are observed. At 130 MeV for A (xy) such discrepancies usually appear, or are enhanced, when model 3N forces are included. Predicted effects of 3NFs are much lower at 100 MeV and at this energy equally good consistency between the data and the calculations is obtained with or without 3NFs.
THREE-NUCLEON INTERACTION DYNAMICS STUDIED VIA THE DEUTERON-PROTON BREAKUP
E. Stephan, S. Kistryn, N. Kalantar-Nayestanaki, A. Biegun, K. Bodek, I. Ciepal, M. Eslami-Kalantari, V. Jha, DA. Kirillov, DI. Kirillov, M. Kis, S. Kliczewski, B. Klos, A. Kozela, M. Kravcikova, VM. Kyryanchuk, M. Lesiak, H. Machner, A. Magiera, M. Mahjour-Shafiei, G. Martinska, J. Messchendorp, A. Micherdzinska, N. Piskunov, D. Protic, A. Ramazani, P. Von Rossen, BJ. Roy, H. Sakai, K. Sekiguchi, I. Sitnik, R. Siudak, R. Sworst, J. Urban, J. Zejma, W. Zipper
abstract
Rich sets of high precision cross sections, vector and tensor analyzing powers for the H-1((d) over right arrow, pp)n breakup reaction were measured at 130 and 100 MeV beam energy with the use of detection systems covering large parts of the phase space. The cross section data allowed to establish evidences for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force in the breakup reaction. Analyzing power data are generally quite well described by theoretical predictions even with pure nucleon-nucleon interactions. However, in some regions discrepancies has been observed for tensor analyzing powers at 130 MeV.
Comparison of nonequilibrium processes in p plus Ni and p plus Au collisions at GeV energies
A. Budzanowski, M. Fidelus, D. Filges, F. Goldenbaum, H. Hodde, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, S. Kliczewski, A. Kowalczyk, E. Kozik, P. Kulessa, H. Machner, A. Magiera, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, R. Siudak, M. Wojciechowski
abstract
The energy and angular dependence of double differential cross sections d(2)sigma/d Omega dE were measured for p, d, t, He-3,He-4,He-6, Li-6,Li-7,Li-8, Be-7,Be-9,Be-10, B-10,B-11, and C produced in collisions of 1.2, 1.9, and 2.5 GeV protons with a Ni target. The shape of the spectra and angular distributions almost does not change whereas the absolute value of the cross sections increases by a factor similar to 1.7 for all ejectiles in this beam energy range. It was found that energy and angular dependencies of the cross sections cannot be reproduced by microscopic models of intranuclear cascade including coalescence of nucleons coupled to statistical model for evaporation of particles from excited, equilibrated residual nuclei. The inclusion of nonequilibrium processes, described by a phenomenological model of the emission from fast and hot moving sources, resulting from break up of the target nucleus, leads to very good reproduction of data. Cross sections of these processes are quite large, exhausting approximately half of the total production cross sections. Due to good reproduction of energy and angular dependencies of d(2)sigma/d Omega dE it was possible to determine total production cross sections for all studied ejectiles. Results obtained in this work point to the analogous reaction mechanism for proton induced reactions on Ni target as that observed previously for Au target in the same beam energy range.
Vector and tensor analyzing powers in deuteron-proton breakup at 130 MeV
E. Stephan, S. Kistryn, R. Sworst, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, AC. Fonseca, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, B. Klos, A. Kozela, M. Mahjour-Shafiei, A. Micherdzinska, A. Nogga, R. Skibiński, H. Witała, A. Wronska, J. Zejma, W. Zipper
abstract
High-precision data for vector and tensor analyzing powers for the H-1((d) over right arrow, pp)n reaction at a 130-MeV deuteron beam energy have been measured over a large part of the phase space. Theoretical predictions based on various approaches to describe the three nucleon (3N) system reproduce very well the vector analyzing power data and no three-nucleon force effect is observed for these observables. Tensor analyzing powers are also very well reproduced by calculations in almost the whole studied region, but locally certain discrepancies are observed. For A(xy) such discrepancies usually appear, or are enhanced, when model 3N forces, TM99 or Urbana, are included. Problems of all theoretical approaches with describing A(xx) and A(yy) are limited to very small kinematical regions, usually characterized by the lowest energy of the relative motion of the two protons.
Vector and tensor analyzing powers in deuteron-proton breakup at 130 MeV
E. Stephan, S. Kistryn, R. Sworst, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, AC. Fonseca, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, B. Klos, A. Kozela, M. Mahjour-Shafiei, A. Micherdzinska, A. Nogga, R. Skibinski, H. Witala, A. Wronska, J. Zejma, W. Zipper
abstract
High-precision data for vector and tensor analyzing powers for the H-1((d) over right arrow, pp)n reaction at a 130-MeV deuteron beam energy have been measured over a large part of the phase space. Theoretical predictions based on various approaches to describe the three nucleon (3N) system reproduce very well the vector analyzing power data and no three-nucleon force effect is observed for these observables. Tensor analyzing powers are also very well reproduced by calculations in almost the whole studied region, but locally certain discrepancies are observed. For A(xy) such discrepancies usually appear, or are enhanced, when model 3N forces, TM99 or Urbana, are included. Problems of all theoretical approaches with describing A(xx) and A(yy) are limited to very small kinematical regions, usually characterized by the lowest energy of the relative motion of the two protons.
Variation of nonequilibrium processes in the p plus Ni system with beam energy
A. Budzanowski, M. Fidelus, D. Filges, F. Goldenbaum, H. Hodde, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, S. Kliczewski, A. Kowalczyk, E. Kozik, P. Kulessa, H. Machner, A. Magiera, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, R. Siudak, M. Wojciechowski
abstract
The energy and angular dependence of double differential cross sections d(2)sigma/d Omega dE were measured for p,d,t,(3,4)He, (6,7)Li, (7,9)Be, and (10,11)B produced in collisions of 0.175 GeV protons with a Ni target. The analysis of measured differential cross sections allowed the extraction of total production cross sections for the ejectiles listed above. The shape of the spectra and angular distributions indicates the presence of other nonequilibrium processes besides the emission of nucleons from the intranuclear cascade and the evaporation of various particles from remnants of intranuclear cascade. These nonequilibrium processes consist of the coalescence of nucleons into light-charged particles during the intranuclear cascade, of the fireball emission, which contributes to the cross sections of protons and deuterons, and of the breakup of the target nucleus, which leads to the emission of intermediate mass fragments. All such processes were found earlier at beam energies 1.2, 1.9, and 2.5 GeV for Ni and Au targets; however, significant differences in the properties of these processes at high and low beam energy are observed in the present study.
Precise set of tensor analyzing power T-20 data for the deuteron-proton breakup at 130 MeV
E. Stephan, S. Kistryn, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, AC. Fonseca, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, B. Klos, A. Kozela, M. Mahjour-Shafiei, A. Micherdzinska, A. Nogga, R. Skibiński, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
High-precision tensor analyzing power T-20 data of the H-1(d, pp)n reaction at 130 MeV beam energy have been determined for 81 kinematical configurations. They are compared to theoretical predictions based on various approaches to describe the dynamics of the three-nucleon (3N) system. The calculations are performed using modern realistic nucleon-nucleon potentials combined with three-nucleon force (3NF) models or with an effective 3NF resulting from the explicit treatment of the Delta-isobar in coupled-channels (CC) calculations. Alternatively, the framework of chiral perturbation theory is used to generate consistent two-nucleon and three-nucleon potentials at the currently numerically attainable order. Results of the CC calculations with the Delta degrees of freedom and including long-range Coulomb force are also shown. In general all predictions are consistent with each other and describe the experimental T-20 results quite well. In a few configurations small inconsistencies between the data and the results of all approaches are observed. Predicted effects of the 3NF are not big and in most cases do not lead to an improved description of the data. The Coulomb force effects are also small in size and often opposite to the effects of TM99 3NF.
Measurement of the eta -> 3 pi(0) Dalitz plot distribution with the WASA detector at COSY
C. Adolph, M. Angelstein, M. Bashkanov, U. Bechstedt, S. Belostotski, M. Berlowski, H. Bhatt, J. Bisplinghoff, A. Bondar, B. Borasoy, M. Buscher, H. Calen, K. Chandwani, H. Clement, E. Czerwinski, R. Czyzykiewicz, G. D'Orsaneo, D. Duniec, C. Ekstrom, R. Engels, W. Erven, W. Eyrich, P. Fedorets, O. Felden, K. Fransson, D. Gil, F. Goldenbaum, K. Grigoryev, A. Heczko, C. Hanhart, V. Hejny, F. Hinterberger, M. Hodana, B. Hoistad, A. Izotov, M. Jacewicz, M. Janusz, BR. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, I. Keshelashvili, O. Khakimova, A. Khoukaz, K. Kilian, N. Kimura, S. Kistryn, J. Klaja, P. Klaja, H. Kleines, B. Klos, A. Kowalczyk, F. Kren, W. Krzemien, P. Kulessa, S. Kullander, A. Kupsc, A. Kuzmin, V. Kyryanchuk, J. Majewski, H. Machner, A. Magiera, R. Maier, R. Marciniewski, W. Migdal, UG. Meissner, et al.
abstract
In the first production run of the WASA experiment at COSY, the eta decay into three neutral pions was measured in proton-proton interactions at a proton beam kinetic energy of 1.4 GeV. The Dalitz plot of the three pious was Studied using 1.2 x 10(5) fully reconstructed events. and the quadratic slope parameter alpha was determined to be -0.027 +/- 0.008(stat) +/- 0.005(syst). The result is consistent with previous measurements and further corroborates the importance of pion-pion final state interactions. (C) 2009 Elsevier B.V. All rights reserved.
THREE-NUCLEON INTERACTION DYNAMICS STUDIED VIA THE DEUTERON-PROTON BREAKUP
E. Stephan, S. Kistryn, N. Kalantar-Nayestanaki, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, W. Glockle, J. Golak, V. Jha, H. Kamada, D. Kirillov, D. Kirillov, M. Kis, S. Kliczewski, B. Klos, A. Kozela, M. Kravcikova, VM. Kyryanchuk, M. Lesiak, H. Machner, A. Magiera, M. Mahjour-Shafiei, G. Martinska, J. Messchendorp, A. Micherdzinska, A. Nogga, N. Piskunov, D. Protic, A. Ramazani, P. Von Rossen, BJ. Roy, H. Sakai, PU. Sauer, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibinski, R. Sworst, J. Urban, H. Witala, J. Zejma, W. Zipper
abstract
A large set of high precision cross sections, vector A(x), A(y) and tensor A(xx), A(xy), A(yy) analyzing powers for the (1)H((d) over right arrow ,pp)n breakup reaction were measured at 130 MeV beam energy with the detection system covering a large part of the phase space. Results are compared with rigorous theoretical calculations employing various models of the three-nucleon system dynamics. The cross section data allowed to establish evidence for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force in the breakup reaction. Analyzing power data are generally quite well described by theoretical predictions even with pure NN interactions. However, in some regions discrepancies has been observed for tensor analyzing powers, only rarely cured by inclusion of the three nucleon force. This indicates incompletness of the present-day treatment of the spin part of three nucleon system dynamics.
THREE-NUCLEON INTERACTION DYNAMICS STUDIED VIA THE DEUTERON-PROTON BREAKUP
E. Stephan, S. Kistryn, N. Kalantar-Nayestanaki, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, M. Eslami-Kalantari, AC. Fonseca, W. Glockle, J. Golak, V. Jha, H. Kamada, D. Kirillov, D. Kirillov, M. Kis, S. Kliczewski, B. Klos, A. Kozela, M. Kravcikova, VM. Kyryanchuk, M. Lesiak, H. Machner, A. Magiera, M. Mahjour-Shafiei, G. Martinska, J. Messchendorp, A. Micherdzinska, A. Nogga, N. Piskunov, D. Protic, A. Ramazani, P. Von Rossen, BJ. Roy, H. Sakai, PU. Sauer, K. Sekiguchi, I. Sitnik, R. Siudak, R. Skibiński, R. Sworst, J. Urban, H. Witała, J. Zejma, W. Zipper
abstract
A large set of high precision cross sections, vector A(x), A(y) and tensor A(xx), A(xy), A(yy) analyzing powers for the (1)H((d) over right arrow ,pp)n breakup reaction were measured at 130 MeV beam energy with the detection system covering a large part of the phase space. Results are compared with rigorous theoretical calculations employing various models of the three-nucleon system dynamics. The cross section data allowed to establish evidence for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force in the breakup reaction. Analyzing power data are generally quite well described by theoretical predictions even with pure NN interactions. However, in some regions discrepancies has been observed for tensor analyzing powers, only rarely cured by inclusion of the three nucleon force. This indicates incompletness of the present-day treatment of the spin part of three nucleon system dynamics.
Studies of the three-nucleon system dynamics: Cross sections of the deuteron-proton breakup at 130 MeV
S. Kistryn, E. Stephan, N. Kalantar-Nayestanaki, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, AC. Fonseca, W. Glockle, J. Golak, H. Kamada, M. Kis, B. Klos, A. Kozela, A. Nogga, M. Mahjour-Shafiei, A. Micherdzinska, PU. Sauer, R. Skibiński, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
The three-nucleon system is the simplest non-trivial testing ground in which the quality of modern nucleon-nucleon interaction models, as well as additional dynamical ingredients referred to as three-nucleon forces, can be probed quantitatively by means of a rigorous technique of solving the Faddeev equations. A large set of high precision, exclusive cross-section data for the (1)H((d) over right arrow, pp)n breakup reaction at 130 MeV was obtained at KVI, Groningen. It allowed to establish for the first time a clear evidence of the three-nucleon force contributions to the cross sections of the breakup process and to confirm recent predictions of sizable influences of the Coulomb force in this reaction.
Competition of coalescence and "fireball" processes in nonequilibrium emission of light charged particles from p+Au collisions
A. Budzanowski, M. Fidelus, D. Filges, F. Goldenbaum, H. Hodde, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, S. Kliczewski, A. Kowalczyk, E. Kozik, P. Kulessa, H. Machner, A. Magiera, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, R. Siudak, M. Wojciechowski
abstract
The energy and angular dependence of the double differential cross sections d(2)sigma/d Omega dE were measured for p, d, t,He-3,He-4,He-6, Li-6,Li-7,Li-8,Li-9, Be-7,Be-9,Be-10, and B-10,B-11,B-12 isotopes produced in reactions of 1.2- and 1.9-GeV protons on a Au target. The beam energy dependence of the data, supplemented by the cross sections from a previous experiment at 2.5 GeV, is very smooth. The shape of the spectra and angular distributions do not change significantly in the beam energy range from 1.2 to 2.5 GeV. However, the absolute value of the cross sections increases for all ejectiles. The intermediate mass fragment spectra and their angular distributions are very well reproduced by a phenomenological model of two emitting, moving sources, with parameters smoothly varying with energy. The double differential cross sections for light charged particles were analyzed in the framework of the microscopic model calculations of intranuclear cascade, including the coalescence of nucleons and a statistical model for evaporation of particles from excited residual nuclei. However, the energy and angular dependencies of the data agree with neither predictions of the microscopic intranuclear cascade calculations for protons nor the coalescence calculations for other light charged particles. A very good description of the data is achieved by the phenomenological inclusion of the emission of light charged particles from a "fireball" (i.e., a fast and hot moving source). It was found that the nonequilibrium processes are very important for the production of light charged particles. They exhaust 40%-80% of the total cross section-depending on the emitted particles. Coalescence and fireball emission yield comparable contributions to the cross sections with the exception of the He-3 data where coalescence clearly dominates. For all light charged particles, the ratio of nonequilibrium processes to processes proceeding through a phase of statistical equilibrium does not change significantly between the beam energies of 1.2 and 2.5 GeV.
Influence of three-nucleon force effects on polarization observables of the H-1((d)over-bar,pp)n breakup reaction at 130 mev
R. Sworst, S. Kistryn, E. Stephan, A. Biegun, K. Bodek, I. Ciepal, E. Epelbaum, W. Gloeckle, J. Golak, N. Kalantar-Nayastenaki, H. Kamada, B. Klos, A. Kozela, A. Nogga, R. Skibiński, H. Witała, J. Zejma, W. Zipper
abstract
High-precision vector and tensor breakup analyzing powers for the reaction H-1((d) over bar ,pp)n at 130 MeV were evaluated for a large phase space region. Results are compared with rigorous theoretical calculations based on realistic nucleon-nucleon potentials as well as on chiral perturbation theory approach. Theoretical predictions generally describe data quite well, only in a few cases influence of three-nucleon forces is significant.
Vector and tensor analyzing powers of elastic deuteron-proton scattering at 130 MeV deuteron beam energy
E. Stephan, S. Kistryn, R. Sworst, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, A. Fonseca, W. Glockle, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, A. Kozela, M. Mahjour-Shafiei, A. Micherdzinska, A. Nogga, PU. Sauer, R. Skibiński, H. Witała, J. Zejma, W. Zipper
abstract
High precision vector and tensor analyzing power data of the deuteron-proton elastic scattering at 130 MeV deuteron beam energy have been measured in a large range of angles. They are compared with theoretical predictions obtained in various approaches: with realistic potentials for pure NN interactions, with the inclusion of a three-nucleon force, and in the framework of chiral perturbation theory. All the theoretical calculations describe roughly the main features of the measured distributions, but none of them can reproduce all their details. This indicates the need for further development of the three-nucleon force models.
Non-equilibrium emission of complex fragments from p plus Au collisions at 2.5 GeV proton beam energy
A. Bubak, A. Budzanowski, D. Filges, F. Goldenbaum, A. Heczko, H. Hodde, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, S. Kliczewski, A. Kowalczyk, E. Kozik, P. Kulessa, H. Machner, A. Magiera, W. Migdal, N. Paul, B. Piskor-Ignatowicz, M. Puchala, K. Pysz, Z. Rudy, R. Siudak, M. Wojciechowski, P. Wustner
abstract
The energy and angular dependence of double differential cross sections d(2)sigma/d Omega dE was measured for reactions induced by 2.5 GeV protons on Au target with isotopic identification of light products (H, He, Li, Be, and B) and with elemental identification of heavier intermediate mass fragments (C, N, O, F, Ne, Na, Mg, and Al). It was found that two different reaction mechanisms give comparable contributions to the cross sections. The intranuclear cascade of nucleon-nucleon collisions followed by evaporation from an equilibrated residuum describes the low energy part of the energy distributions whereas another reaction mechanism is responsible for the high energy part of the spectra of composite particles. A phenomenological model description of the differential cross sections by isotropic emission from two moving sources led to a very good description of all measured data. Values of the extracted parameters of the emitting sources are compatible with the hypothesis claiming that high energy particles emerge from preequilibrium processes consisting in a breakup of the target into three groups of nucleons; small, fast, and hot fireball of similar to 8 nucleons, and two larger, excited prefragments, which emit light charged particles and intermediate mass fragments. The smaller of them contains similar to 20 nucleons and moves with a velocity larger than the CM velocity of the proton projectile and the target. The heavier prefragment behaves similarly as the heavy residuum of the intranuclear cascade of nucleon-nucleon collisions.
Cross sections of the deuteron-proton breakup as a probe of three-nucleon system dynamics
S. Kistryn, E. Stephan, N. Kalantar-Nayestanaki, A. Biegun, B. Klos, Z. Sworst, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, AC. Fonseca, W. Gloeckle, J. Golak, H. Kamada, M. Ki, A. Kozela, M. Mahjour-Shafiei, A. Micherdzinska, A. Nogga, PU. Sauer, R. Skibiński, H. Witała, J. Zejma, W. Zipper
abstract
The three-nucleon system is the simplest, non-trivial testing ground which allows one to probe quantitatively modern nucleon-nucleon interaction models. The rigorous technique of solving the Faddeev equations for the three-nucleon system allows one to test the influence of additional dynamical ingredients, referred to as three-nucleon forces, as well as the Coulomb interaction and relativistic effects. A large set of high precision, exclusive cross-section data for the H-1(d,pp)n breakup reaction at 130 MeV was obtained at KVI, Groningen. This allowed us to establish for the first time clear evidence for three-nucleon force contributions to the cross sections of the breakup process and to confirm recent predictions of a sizable influence of the Coulomb force in this reaction.
A large, precise set of polarization observables for deuteron-proton breakup at 130 MeV
E. Stephan, S. Kistryn, N. Kalantar-Nayestanaki, A. Biegun, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaun, AC. Fonseca, W. Gloeckle, J. Golak, H. Kamada, M. Kis, B. Klos, A. Kozela, M. Malljour-Shafiei, A. Micherdzinska, A. Nogga, PU. Sauer, R. Skibiński, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
High precision vector A(x), A(y) and tensor A(xx), A(xy), A(yy) analyzing powers for the H-1((d) over right arrow, pp)n breakup reaction were measured at 130 MeV beam energy with the detection system covering a large part of the phase space. Results are compared with rigorous theoretical calculations based on realistic nucleon-nucleon potentials, also with a so-called three-nucleon force included, as well as on chiral perturbation theory. Theoretical predictions generally describe the data quite well, but in some regions discrepancies have been observed, which indicate incompleteness of the present-day treatment of three nucleon dynamics.
Three-nucleon force effects in observables for dp breakup at 130 MeV
A. Biegun, B. Klos, A. Micherdzinska, E. Stephan, W. Zipper, K. Bodek, J. Golak, S. Kistryn, J. Kuros-ZoLnierczuk, R. Skibiński, R. Sworst, H. WitaLa, J. Zejma, A. Kozela, W. Glokle, H. Kamada, E. Epelbaum, A. Nogga, P. Sauer, A. Deltuva
abstract
Measurement of the cross section and spin observables for the kinematically complete H-1((d) over right arrow, pp)n breakup process was carried out at 130 MeV beam energy. The obtained cross section results, spanning the large part of the phase space, are compared with the theoretical predictions based on realistic potentials and ChPT. Confronting the calculated cross sections with the experimental data shows a clear advantage of the predictions in which the 3NF contributions are included. Non-negligible Coulomb effects have been also observed in some kinematical regions.
Muon decay: Measurement of the transverse e(+) polarization and its implications on G(F) and time reversal invariance
W. Fetscher, K. Bodek, N. Danneberg, L. Jarczyk, K. Kirch, S. Kistryn, K. Kohler, J. Lang, A. Kozela, T. Schweizer, J. Smyrski, E. Stephan, A. Strzalkowski, A. von Allmen, J. Zejma
abstract
The transverse polarization components of the e(+) from the decay of polarized mu(+) have been measured at the Paul Scherrer Institute by annihilating in flight the decay positrons with polarized electrons. The use of a stroboscopic method greatly reduces systematic errors. The energy dependence of the transverse polarization component P-T1, which lies in the plane defined by muon spin and positron momentum, yields the low energy parameter eta = (-2 +/- 8) X 10(-3) and thus an improved model-independent value of the Fermi coupling constant. For the transverse polarization P-T2, averaged over the positron energy, we obtain (P-T2) = (-4 +/- 8) x 10(-3). This improves the previous limit on the violation of time invariance in muon decay [1] by a factor of three.
Light charged particle and intermediate mass fragment cross-sections in GeV proton-induced reactions
V. Bollini, A. Bubak, A. Budzanowski, J. Cugnon, D. Filges, F. Goldenbaum, A. Heczko, H. Hodde, L. Jarczyk, B. Kamys, M. Kistryn, S. Kistryn, S. Kliczewski, A. Kowalczyk, P. Kulessa, H. Machner, A. Magiera, W. Migdal, K. Nunighoff, N. Paul, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, R. Siudak, M. Wojciechowski, E. Kozik
abstract
As an international collaboration PISA (Proton Induced SpAllation) has initiated measurements of total and double differential cross-sections for products of spallation reactions at the proton accelerator COSY in Julich (Germany) in order to study secondary particle production created in structural, window, and target materials by proton beams up to 2.5 GeV incident kinetic energy. In the framework of Spallation Neutron Sources and accelerator-driven systems, residual nuclei (H, He up to intermediate mass fragrments) production cross-sections are of great importance for estimation of damage in target and structural materials. Reliable and comprehensive experimental data, especially for p-energies beyond I GeV will serve as benchmarks for code development and validation. Data taken by Bragg curve spectroscopy and silicon detector telescopes for the reaction 1.9 GeV p + Ni(Au) will be discussed and kinetic energy spectra of light ions and intermediate mass fragments will be presented. (c) 2006 Elsevier B.V. All rights reserved.
Three-nucleon force effects in the analyzing powers of the (d)over-right-arrowp breakup at 130 MeV
A. Biegun, E. Stephan, S. Kistryn, K. Bodek, I. Ciepal, A. Deltuva, E. Epelbaum, W. Glockle, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, B. Klos, A. Kozela, J. Kuros-Zolnierczuk, M. Mahjour-Shafiei, UG. Meissner, A. Micherdzinska, A. Nogga, PU. Sauer, R. Skibiński, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
A measurement of the analyzing powers for the H-1((d) over right arrow pp)n breakup reaction at 130 MeV polarized deuteron beam energy was carried out at KVI Groningen. The experimental setup covered a large fraction of the phase space. Obtained tensor analyzing powers T-22 for selected kinematical configurations have been compared to theoretical predictions based on various approaches: the rigorous Faddeev calculations using the realistic nucleon-nucleon potentials with and without three nucleon force (3NF) models, predictions of the chiral perturbation theory, and coupled channel calculations with the explicit Delta degrees of freedom. In the presented configurations the results of all predictions are very close to one another and there are no significant 3NF influences. Not all of the data can be satisfactory reproduced by the theoretical calculations.
Muon decay: Measurement of the transverse e(+) polarization and its implications on G(F) and time reversal invariance
W. Fetscher, K. Bodek, N. Danneberg, L. Jarczyk, K. Kirch, S. Kistryn, K. Kohler, J. Lang, A. Kozela, T. Schweizer, J. Smyrski, E. Stephan, A. Strzalkowski, A. von Allmen, J. Zejma
abstract
The transverse polarization components of the positrons from the decay of polarized muons have been measured at the Paul Scherrer Institute by annihilating in flight the decay positrons with polarized electrons. The use of a stroboscopic method greatly reduces systematic errors. The energy dependence of the transverse polarization component P-TI, which lies in the plane defined by muon spin and positron momentum, yields the low energy parameter eta = (-2 +/- 8) x 10(-3) and thus an improved model-independent value of the Fermi coupling constant. For the transverse polarization P-T2, averaged over the positron energy, we obtain (P-T2) = (-4 +/- 8) x 10(-3). This improves the previous limit on the violation of time invariance in muon decay [1] by a factor of three.
Measurement of the transverse e(+) polarization from the decay of polarized mu(+) and its implications on G(F) and time reversal invariance
W. Fetscher, K. Bodek, N. Danneberg, L. Jarczyk, S. Kistryn, K. Kohler, K. Kirch, A. Kozela, J. Lang, J. Smyrski, T. Schweizer, E. Stephan, A. Strzalkowski, J. Zejma, A. von Allmen
abstract
The transverse polarization of the e(+) from the decay of polarized mu(+) has been measured at the Paul Scherrer Institute. From the energy dependence of the transverse polarization component P-T1, which lies in the plane spanned by muon spin and positron momentum, the decay parameters mu and mu '' are derived, the first of which yields an improved model-independent value of the Fermi coupling constant. A non-zero value of the transverse component P-T2, which is perpendicular to the plane mentioned above, would be the first observation of time reversal violation in a purely leptonic decay. From the energy dependence of P-T2 the two decay parameters alpha'/A and beta'/A are deduced. Part of the data (40 x 10(8) annihilation events) have been evaluated. Both P-T1 and P-T2 averaged over the positrons' energy, are consistent with zero in full agreement with the standard model. The precision obtained is Delta < P-T1> = Delta < P-T2> = 8 x 10(-3). which is an improvement by a factor of three as compared to the results of the previous experiment [1].
Systematic study of three-nucleon force effects in the cross section of the deuteron-proton breakup at 130 MeV
S. Kistryn, E. Stephan, A. Biegun, K. Bodek, A. Deltuva, E. Epelbaum, K. Ermisch, W. Glockle, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, B. Klos, A. Kozela, J. Kuros-Zolnierczuk, M. Mahjour-Shafiei, UG. Meissner, A. Micherdzinska, A. Nogga, PU. Sauer, R. Skibiński, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
High-precision cross-section data of the deuteron-proton breakup reaction at 130 MeV are presented for 72 kinematically complete configurations. The data cover a large region of the available phase space, divided into a systematic grid of kinematical variables. They are compared with theoretical predictions, in which the full dynamics of the three-nucleon (3N) system is obtained in three different ways: realistic nucleon-nucleon (NN) potentials are combined with model 3N forces (3NF's) or with an effective 3NF resulting from explicit treatment of the Delta-isobar excitation. Alternatively, the chiral perturbation theory approach is used at the next-to-next-to-leading order with all relevant NN and 3N contributions taken into account. The generated dynamics is then applied to calculate cross-section values by rigorous solution of the 3N Faddeev equations. The comparison of the calculated cross sections with the experimental data shows a clear preference for the predictions in which the 3NF's are included. The majority of the experimental data points are well reproduced by the theoretical predictions. The remaining discrepancies are investigated by inspecting cross sections integrated over certain kinematical variables. The procedure of global comparisons leads to establishing regularities in disagreements between the experimental data and the theoretically predicted values of the cross sections. They indicate deficiencies still present in the assumed models of the 3N system dynamics.
Muon decay: Measurement of the transverse polarization of the decay positrons and its implications for the Fermi coupling constant and time reversal invariance
N. Danneberg, W. Fetscher, KU. Kohler, J. Lang, T. Schweizer, A. von Allmen, K. Bodek, L. Jarczyk, S. Kistryn, J. Smyrski, A. Strzalkowski, J. Zejma, K. Kirch, A. Kozela, E. Stephan
abstract
The two transverse polarization components P-T1 and P-T2 of the e(+) from the decay of polarized mu(+) have been measured as a function of the e(+) energy. Their energy averaged values are
=(6.3+/-7.7+/-3.4)x10(-3) and =(-3.7+/-7.7+/-3.4)x10(-3). From the energy dependence of P-T1 and P-T2 the decay parameters eta,eta('') and alpha(')/A,beta(')/A are derived, respectively. Assuming only one additional coupling besides the dominant V-A interaction one gets improved limits on eta, beta(')/A, and the scalar coupling constant g(RR)(S): eta=(-2.1+/-7.0+/-1.0)x10(-3), beta(')/A=(-1.3+/-3.5+/-0.6)x10(-3), Re{g(RR)(S)}=(-4.2+/-14.0+/-2.0)x10(-3), and Im{g(RR)(S)}=(5.2+/-14.0+/-2.4)x10(-3).Analyzing power measurement in deuteron-proton breakup at 130 MeV
E. Stephan, A. Biegun, S. Kistryn, K. Bodek, W. Glockle, J. Golak, N. Kalantar-Nayestanaki, A. Kis, B. Klos, A. Kozela, J. Kuros-Zolnierczuk, A. Micherdzinska, M. Mahjour-Shafiei, R. Skibiński, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
Vector and tensor analyzing powers of the H-1((d) over right arrow ,pp)n breakup process have been measured at the beam energy of 130 MeV. The forthcoming results will be compared with predictions based on various 2N and 3N forces models in quest for a correct structure of the 3NF.
Cross sections of the deuteron-proton breakup at 130 MeV
S. Kistryn, A. Biegun, E. Stephan, B. Klos, K. Bodek, K. Ermisch, W. Glockle, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, A. Kozela, J. Kuros-Zolnierczuk, A. Micherdzinska, M. Mahjour-Shafiei, A. Nogga, R. Skibiniski, R. Sworst, H. Witała, J. Zejma, W. Zipper
abstract
Comparison of the cross sections measured over a large part of the phase space of the deuteron-proton breakup at 130 MeV with the results of rigorous, Faddeev-like calculations is presented. Global analysis, including nearly 1200 data points, reveals a better agreement for theoretical predictions which include three-nucleon force (3NF) model over the results obtained with only nucleon-nucleon realistic potentials. A possible way to probe details of the 3NF models via studying "non-standard" projections of the multi-dimensional phase space is envisaged.
PISA - an experiment for fragment spectroscopy at the Internal Beam of COSY: application of an Axial Ionization Chamber
R. Barna, V. Bollini, A. Bubak, A. Budzanowski, D. De Pasquale, D. Filges, SV. Fortsch, F. Goldenbaum, A. Heczko, H. Hodde, A. Italiano, L. Jarczyk, B. Kamys, J. Kisiel, M. Kistryn, S. Kistryn, S. Kliczewski, A. Kowalczyk, P. Kulessa, H. Machner, A. Magiera, J. Majewski, W. Migdal, H. Ohm, N. Paul, B. Piskor-Ignatowicz, K. Pysz, Z. Rudy, H. Schaal, R. Siudak, E. Stephan, GF. Steyn, R. Sworst, T. Thovhogi, M. Wojciechowski, W. Zipper
abstract
The Proton-Induced SpAllation (PISA) experiment performed at the internal beam facility of the COSY storage ring in Julich, Germany, which is aimed at the precise measurement of double differential cross-sections over a broad range of energies and angles for spallation reactions induced by protons of 200-2500 MeV energy in various targets, is presented. In this paper the emphasis is put on the design, principles of operation and performance of a Bragg Curve Detector (BCD) optimized for internal beam experiments at storage rings. Very clean and distinct product identification (with Z up to similar to 14) from reactions, in which a Ni target was bombarded with a 1.9 GeV circulating proton beam, is obtained. The individual elements are resolved for emission energies higher than 0.5 MeV/nucleon. Moreover, due to the detector readout achieved by coupling a specially designed current sensitive preamplifier directly to a sampling ADC, the shape analysis of the signals from the BCD allows the isotope identification of light particles with A up to similar to 11. It is also found that the BCD can be used efficiently as a thin DeltaE detector for the telescope consisting of the BCD and a series of silicon detectors. (C) 2003 Elsevier B.V. All rights reserved.
Isospin symmetry breaking as a tool for particle physics investigations
A. Magiera, S. Abdel-Bary, P. Hawranek, J. Ilieva, K. Kilian, D. Kirilov, S. Kistryn, S. Kliczewski, W. Klimala, D. Kolev, M. Kravcikova, T. Kutsarova, J. Lieb, H. Machner, G. Martinska, L. Pentchev, N. Piskunov, P. von Rossen, BJ. Roy, I. Sitnik, R. Siudak, J. Smyrski, R. Tsenov, M. Ulicny, J. Urban, A. Wronska
abstract
The importance of the isospin symmetry breaking in extracting various particle physics parameters is discussed. In particular the measurement of isospin symmetry breaking in the reaction pd --> (3)Hpi(+)/(3)Hepi(0) is presented. The energy dependence of the measured cross sections ratio indicate isospin symmetry breaking effects. Within a simple model based on pi(0) - eta meson mixing the mixing angle of these mesons is extracted.
Measurement of the transverse polarization of the e(+) from the decay of polarized mu(+)
W. Fetscher, K. Bodek, A. Budzanowski, N. Danneberg, C. Hilbes, L. Jarczyk, K. Kirch, S. Kistryn, K. Kohler, J. Lang, A. Kozela, J. Smyrski, E. Stephan, A. Strzalkowski, A. von Allmen, J. Zejma
abstract
The transverse polarization components of the positrons from the decay of polarized muons have been measured at the Paul Scherrer Institute by annihilating in flight the decay positrons with polarized electrons. The use of a stroboscopic method greatly reduces systematic errors. The energy dependence of the transverse polarization component P-T1, which lies in the plane spanned by muon spin and positron momentum, yields the low energy parameter eta and thus an improved model-independent value of the Fermi coupling constant. A non-zero value of the transverse component P-T2, which is perpendicular to the plane mentioned above, would be the first observation of time reversal violation in a purely leptonic decay. Part of the data (40 x 10(8) annihilation events) have been evaluated. Both P-T1 and P-T2, averaged over the positrons' energy, are consistent with zero with a precision improved by a factor of three as compared with the previous measurement [1]. The preliminary results are
= (7 +/- 8) x 10(-3), = (-1 +/- 8) x 10(-3) in full agreement with the standard model.Evidence of three-nucleon force effects from 130 MeV deuteron-proton breakup cross section measurement
S. Kistryn, A. Micherdzinska, R. Bieber, A. Biegun, K. Bodek, K. Ermisch, W. Glockle, J. Golak, N. Kalantar-Nayestanaki, H. Kamada, M. Kis, A. Kozela, J. Kuros-Zolnierczuk, A. Nogga, M. Mahjour-Shafiei, R. Skibiński, E. Stephan, H. Witała, J. Zejma, W. Zipper
abstract
The measurement of exclusive deuteron-proton breakup for kinematics covering a large fraction of the available phase space has been performed using 130 MeV deuteron beam. High precision fivefold cross section data in 38 kinematical configurations have been compared to predictions of modern nuclear forces. To this aim the three-nucleon (3N) Faddeev equations have been solved rigorously using the nucleon-nucleon (NN) potentials AV18, charge-dependent Bonn, Nijm I, and Nijm II alone, and combining them with the 2pi -exchange Tucson-Melbourne three-nucleon force (TM 3NF ) and with its modified version TM99, more consistent with chiral symmetry. The AV18 potential was also combined with the Urbana IX 3NF . Global comparison of the measured cross sections to pairwise NNforce predictions only and with 3NF 's included clearly reveals the presence of 3NF effects. Our study demonstrates the usefulness of the kinematically complete breakup reaction studied in the full phase space to search for 3NF effects.
Measurement of the polarization vector of the e(+) from the decay of polarized mu(+) as a test of time reversal invariance
W. Fetscher, K. Bodek, A. Budzanowski, N. Danneberg, C. Hilbes, L. Jarczyk, K. Kirch, S. Kistryn, J. Klement, K. Kohler, A. Kozela, J. Lang, GL. Llacer, T. Schweizer, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, J. Zejma
abstract
The complete polarization vector of the positrons from the decay of polarized muons has been measured for the first time with one experimental setup. The mu(pT) experiment at the Paul Scherrer Institute determines the three polarization components simultaneously with the same apparatus by making use of three different effects (spatial and temporal dependence of annihilation-in-flight with polarized electrons as well as muon decay asymmetry). The use of a stroboscopic method greatly reduces systematic errors. The energy dependence of the transverse polarization component P-T1, which lies in the plane spanned by muon spin and positron momentum, yields the low energy parameter eta and thus an improved model-independent value of the Fermi coupling constant. A non-zero value of the transverse component P-T2, which is perpendicular to the above-mentioned plane, would be the first observation of time reversal violation in a purely leptonic decay. The preliminary results are P-T1=(5+/-16)x10(-3), P-T2=(1+/-16)x10(-3) and P-L=(1.09+/-0.15).
pi(0)-eta meson mixing in pd -> H-3 pi(+)/He-3 pi(0) reactions
M. Abdel-Bary, P. Hawranek, J. Ilieva, K. Kilian, D. Kirilov, S. Kistryn, S. Kliczewski, W. Klimala, D. Kolev, M. Kravcikova, T. Kutsarova, J. Lieb, H. Machner, A. Magiera, G. Martinska, L. Pentchev, N. Piskunov, P. von Rossen, BJ. Roy, I. Sitnik, R. Siudak, J. Smyrski, R. Tsenov, M. Ulicny, J. Urban, A. Wronska
abstract
Beam momentum dependence of the experimental cross sections for pd-->(3)Hpi(+)/(3)Hepi(0) reactions have been studied at large proton-pion relative angle. The measurements were performed for five beam momenta in the region of the eta meson production threshold. Observed behavior of the measured cross sections ratio reveals manifestations of the isospin symmetry breaking effects. A simple model allows one to interpret the isospin symmetry breaking in terms of pi(0)-eta meson mixing. Based on that model analysis of the experimental results leads to the mixing angle value of 0.006+/-0.005 rad.
Polarized Muon decay: Measurement of the polarization vector of the decay positrons as a test of time reversal invariance
W. Fetscher, K. Bodek, A. Budzanowski, N. Danneberg, C. Hilbes, L. Jarczyk, K. Kirch, S. Kistryn, J. Klement, K. Kohler, A. Kozela, J. Lang, X. Morelle, T. Schweizer, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, J. Zejma
abstract
The mu(PT) experiment at the Paul Scherrer Institut has determined the three polarization components of positrons from polarized muon decay simultaneously with the same apparatus by making use of three different effects (spatial and temporal dependence of annihilation-in-flight with polarized electrons and muon decay asymmetry). The use of a stroboscopic method greatly reduces systematic errors. The energy dependence of the transverse polarization component P-T1, which lies in the plane spanned by muon-spin and positron momentum, yields the low energy parameter eta and thus an improved model-independent value of the Fermi coupling constant. A non-zero value of the transverse component P-T2, which is perpendicular to the above mentioned plane, would be the first observation of time reversal violation in a purely leptonic decay. The preliminary results are P-T1 = (5 +/- 16) X 10(-3), p(T2) = (1 +/- 16) x 10(-3) and P-L = 1.09 +/- 0.15.
Three-nucleon dynamics studied via H-1(d,pp)n breakup at 130 MeV
S. Kistryn, R. Bieber, A. Biegun, K. Bodek, K. Ermisch, W. Glockle, J. Golak, MN. Harake, N. Kalantar-Nayestanaki, H. Kamada, J. Kuros-Zolnierczuk, M. Kis, A. Micherdzinska, A. Nogga, M. Shafiei, R. Skibiński, E. Stephan, H. Witała, J. Zejma, W. Zipper
abstract
An experiment to measure cross sections and both, vector and tensor analyzing powers, for the H-1(d,pp)n breakup reaction at 130 MeV deuteron beam energy is presented. Employing a position-sensitive detection system covering a large solid angle enables probing of a significant part of the whole phase space. First results are presented and compared with the rigorous Faddeev calculations using modern NN and 3NF potentials.
Determination of the polarization of the decay positrons in polarized muon decay
KU. Kohler, K. Bodek, A. Budzanowski, N. Danneberg, W. Fetscher, C. Hilbes, L. Jarczyk, K. Kirch, S. Kistryn, J. Klement, A. Kozela, J. Lang, GL. Llacer, T. Schweizer, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, J. Zejma
abstract
The standard model of electroweak interactions predicts that the positrons from the decay of polarized positive muons are mainly longitudinally polarized. The measurement of the two transverse polarization components of the positron P-T1 and P-T2 is a sensitive tool to look for contributions from additional, exotic interactions and for the violation of time reversal invariance in this purely leptonic decay. The mu(PT)-experiment at the Paul Scherrer Institute determines the three positron polarization components simultaneously with the same apparatus by making use of three different effects. By examining the temporal dependence of annihilation-in-flight of the decay positrons with polarized electrons a possible non-zero value of the transverse polarization is determined. The phase of this transverse polarization can be measured by making use of the decay asymmetry. Using the dependence of annihilation-in-flight on the angle between electron polarization and positron momentum leads to the determination of the longitudinal polarization which not only completes the measurement of the entire polarization vector but also serves as a sensitivity check. In order to deduce the polarization at the time and location of the muon decay a method based on Monte-Carlo simulations with full spin-dependence implemented is being developed.
Magnetic spectrometer Big Karl for studies of meson production reactions
J. Bojowald, A. Budzanowski, A. Chatterjee, J. Ernst, L. Freindl, D. Frekers, P. Hawranek, J. Ilieva, L. Jarczyk, K. Kilian, S. Kistryn, S. Kliczewski, W. Klimala, D. Kolev, M. Kravcikova, T. Kutsarova, J. Lieb, H. Machner, A. Magiera, G. Martinska, L. Pentchev, D. Protic, B. Razen, P. von Rossen, BJ. Roy, R. Siudak, J. Smyrski, A. Strzalkowski, R. Tsenov, M. Ulicny, J. Urban, A. Wronska
abstract
The paper describes modifications of the Julich magnetic spectrometer Big Karl needed to study meson production and especially to investigate charge symmetry breaking effects-an experiment that requires a high-precision measurement. New elements that have been added to Big Karl have extended the spectrometer capabilities to a much wider momentum range. The new features also facilitate simultaneous detection of particles with very different rigidities. The experimental methods for improving background and determining relative acceptance of the spectrometer at various rigidities are presented. (C) 2001 Elsevier Science B.V. All rights reserved.
Forward K+ production in subthreshold pA collisions at 1.0 GeV
V. Koptev, M. Buscher, H. Junghans, M. Nekipelov, K. Sistemich, H. Stroher, V. Abaev, HH. Adam, R. Baldauf, S. Barsov, U. Bechstedt, N. Bongers, G. Borchert, W. Borgs, W. Brautigam, W. Cassing, V. Chernyshev, B. Chiladze, M. Debowski, J. Dietrich, M. Drochner, S. Dymov, J. Ernst, W. Erven, R. Esser, P. Fedorets, A. Franzen, D. Gotta, T. Grande, D. Grzonka, G. Hansen, M. Hartmann, V. Hejny, L. Von Horn, L. Jarczyk, A. Kacharava, B. Kamys, A. Khoukaz, T. Kirchner, S. Kistryn, F. Klehr, HR. Koch, V. Komarov, S. Kopyto, R. Krause, P. Kravtsov, V. Kruglov, P. Kulessa, A. Kulikov, V. Kurbatov, N. Lang, N. Langenhagen, I. Lehmann, A. Lepges, J. Ley, B. Lorentz, G. Macharashvili, R. Maier, S. Martin, S. Merzliakov, K. Meyer, S. Mikirtychiants, H. Muller, P. Munhofen, A. Mussgiller, V. Nelyubin, M. Nioradze, H. Ohm, A. Petrus, et al.
abstract
K+-meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Julich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta less than or equal to 12 degrees, has been measured for a beam energy of T-p = 1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger moments reflect a high degree of collectivity in the target nucleus.
Three-nucleon force effects in the dp-breakup at 130 MeV
S. Kistryn, R. Bieber, K. Bodek, K. Ermisch, W. Glockle, J. Golak, MN. Harakeh, N. Kalantar-Nayestanaki, J. Kuros-Zolnierczuk, H. Kamada, A. Micherdzinska, A. Nogga, R. Skibiński, M. Sokolowski, E. Stephan, A. Strzalkowski, H. Witała, J. Zejma, W. Zipper
abstract
Indications for three nucleon force (3NF) effects in PJd elastic scattering and in specific kinematical configurations of the deuteron breakup reaction became motivation for complex studies of the three nucleon system dynamics in the dp breakup process over a broad region of phase-space. A dedicated experiment is aimed at precise determination of cross sections and both vector and tenser analyzing powers for the H-1((p) over right arrow pp)n breakup reaction at 130 MeV deuteron beam energy. The experiment, employs a position-sensitive detection system covering a large solid angle and allowing for excellent particle identification. The first data taking run has been completed and the accumulated data are being analyzed. The results will be compared with the rigorous calculations within the Faddeev formalism, including various nucleon-nucleon potentials and 3NF models.
Search for three-nucleon force effects in dp-breakup reaction
R. Bieber, K. Bodek, K. Ermisch, W. Glockle, J. Golak, MN. Harakeh, N. Kalantar-Nayestanaki, S. Kistryn, J. Kuros-Zolnierczuk, J. Lang, A. Micherdzinska, R. Skibiński, M. Sokolowski, J. Sromicki, E. Stephan, A. Strzalkowski, M. Volkerts, H. Witała, J. Zejma, W. Zipper
abstract
Proton-induced deuteron breakup reaction at 65 MeV: Unspecific configurations
K. Bodek, J. Golak, L. Jarczyk, S. Kistryn, J. Kuros-Zolnierczuk, J. Lang, A. Micherdzinska, R. Skibiński, J. Smyrski, M. Sokolowski, J. Sromicki, A. Strzalkowski, H. Witała, J. Zejma, W. Zipper
abstract
Cross sections and vector-analyzing powers for four unspecific configurations of the H-2(p,pp)yl breakup reaction at E-p(lab) = 65 MeV were measured in a kinematically complete experiment. Measured observables are compared with rigorous Faddeev calculations using four realistic charge-dependent interaction models, the CD Bonn, Argonne upsilon (18), Nijmegen I, and Nijmegen II potentials with or without inclusion of the Tucson-Melbourne three-nucleon force. Coulomb effects are completely omitted. A satisfactory agreement between theory and experiment has been found. There exist, however, some discrepancies between measured and calculated analyzing-power distributions in certain kinematical regions. The effects of the Tucson-Melbourne three-body force are either negligible or slightly increasing the disagreement.
Proton-induced deuteron breakup reaction at 65 MeV: Unspecific configurations
K. Bodek, J. Golak, L. Jarczyk, S. Kistryn, J. Kuros-Zolnierczuk, J. Lang, A. Micherdzinska, R. Skibinski, J. Smyrski, M. Sokolowski, J. Sromicki, A. Strzalkowski, H. Witala, J. Zejma, W. Zipper
abstract
Cross sections and vector-analyzing powers for four unspecific configurations of the H-2(p,pp)yl breakup reaction at E-p(lab) = 65 MeV were measured in a kinematically complete experiment. Measured observables are compared with rigorous Faddeev calculations using four realistic charge-dependent interaction models, the CD Bonn, Argonne upsilon (18), Nijmegen I, and Nijmegen II potentials with or without inclusion of the Tucson-Melbourne three-nucleon force. Coulomb effects are completely omitted. A satisfactory agreement between theory and experiment has been found. There exist, however, some discrepancies between measured and calculated analyzing-power distributions in certain kinematical regions. The effects of the Tucson-Melbourne three-body force are either negligible or slightly increasing the disagreement.
Polarized muon decay: Measurement of the polarization vector of the decay positrons
K. Bodek, A. Budzanowski, N. Danneberg, W. Fetscher, C. Hilbes, L. Jarczyk, K. Kirch, S. Kistryn, J. Klement, K. Kohler, A. Kozela, J. Lang, GL. Llacer, M. Markiewicz, X. Morelle, T. Schweizer, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, J. Zejma
abstract
In the standard model (SM) Of electroweak interactions the positron from the decay of polarized positive muons is mainly longitudinally polarized. The measurement of the two transverse polarization components, therefore, is a sensitive tool for contributions from additional, exotic, interactions. The energy dependence of the transverse polarization component P-T1, which lies in the plane spanned by muon-spin and positron momentum, yields the low energy parameter eta and thus an improved model-independent value of the Fermi coupling constant. A non-zero value of the transverse component PT2, which is perpendicular to the above mentioned plane, would be the first observation of time reversal violation in a purely leptonic decay. The mu (PT) experiment at the Paul Scherrer Institute determines the three polarization components simultaneously with the same apparatus by making use of three different reactions (spatial and temporal dependence of annihilation-in-flight with polarized electrons as well as muon decay asymmetry). The use of a stroboscopic method greatly reduces systematic errors. The measurement of the longitudinal polarization serves mainly as a test of the sensitivity of the apparatus, while the measurement of the two transverse components will improve the current experimental limits. The preliminary results are P-T1 = (7 +/- 13) x 10(-3), P-T2 = (19 +/- 13) x 10(-3).
An apparatus for the measurement of the transverse polarization of positrons from the decay of polarized muons
IC. Barnett, C. Bee, K. Bodek, A. Budzanowski, N. Danneberg, P. Eberhardt, W. Fetscher, C. Hilbes, M. Janousch, L. Jarczyk, K. Kirch, S. Kistryn, J. Klement, K. Kohler, A. Kozela, J. Lang, G. Llosa, M. Markiewicz, X. Morelle, O. Naviliat, T. Schweizer, J. Smyrski, J. Stromicki, E. Stephan, A. Strzalkowski, K. Szeker, J. Zejma
abstract
An apparatus for the measurement of the two transverse polarization components P-T1 and P-T2 of the positrons from polarized mu (+) decay is described. It makes use of a stroboscopic method which cancels many systematic asymmetries and allows one to use muon stop rates in the order of up to 10(8) s(-1). The experiment aims at an accuracy of DeltaP(T1) = DeltaP(T2), = 3 x 10(-3) and by that at an improvement of the existing limit by nearly one order of magnitude. With these results one will obtain an improved model-independent value for the Fermi coupling constant G(F) and more stringent limits to possible violations of time reversal invariance in a purely leptonic reaction: (C) 2000 Elsevier Science B.V. All rights reserved.
Measurement of the transverse polarization of positrons from the decay of polarized muons: A status report
K. Bodek, A. Budzanowski, N. Danneberg, W. Fetscher, C. Hilbes, M. Janousch, L. Jarczyk, E. Kirch, S. Kistryn, J. Klement, K. Kohler, A. Kozela, J. Lang, GL. Llacer, M. Markiewicz, X. Morelle, T. Schweizer, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, J. Zejma
abstract
A new experiment [1] to measure both transverse components of the positron polarization from the decay of polarized muons starts data taking at PSI in Switzerland. The experiment aims at an accuracy of Delta P-T1 = Delta P-T2 = 3 x 10(-3) and by that at an improvement of the existing limit by nearly one order of magnitude. These results will be sensitive tests for the contribution of exotic couplings to muon decay. In particular, the measurement of P-T1 allows the extraction of the so-called low energy Michel parameter eta, the accuracy of which presently limits a more precise model independent determination of the Fermi coupling constant Gr. The measurement of P-T1 is at present the only possibility to best time reversal invariance in a purely leptonic reaction. The physics motivation is discussed together with a description of the experimental setup and results from test measurements.
Is time reversal invariance violated in muon decay? A measurement of the transverse positron polarization
K. Bodek, A. Budzanowski, N. Danneberg, W. Fetscher, C. Hilbes, L. Jarczyk, K. Kirch, S. Kistryn, J. Klement, K. Kohler, A. Kozela, J. Lang, GL. Llacer, M. Markiewicz, X. Morelle, T. Schweizer, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, J. Zejma
abstract
In the standard model (SM) of electroweak interactions the positron from the decay of polarized positive muons is mainly longitudinally polarized. However the model also predicts a small transverse polarization component P-T1, which lies in the plane spanned by muon-spin and positron momentum. Interference with additional, scalar couplings would result in substantial values for P-T1 as well as in a non-zero Value of the transverse component PT2 which is perpendicular to the above mentioned plane. A nonzero component P-T2, proportional to the imaginary part of a possible scalar coupling, would be the first observation of time reversal violation in a purely leptonic decay. Measuring P-T1, which is proportional to the real part, amounts to a model independent determination of the Fermi-coupling constant. The mu (PT) experiment [1] at the Paul Scherrer Institute will improve the current experimental limits P-T1 = (16 +/- 22) x 10(-3), P-T2 = (7 +/- 23) x 10(-3) by almost one order of magnitude. First preliminary results of the experiment are given.
Proton induced deuteron breakup reaction at 65 MeV: Unspecific configurations
K. Bodek, W. Glockle, J. Golak, L. Jarczyk, S. Kistryn, B. Kozlowska, J. Lang, A. Micherdzinska, O. Naviliat-Cuncic, J. Smyrski, M. Sokolowski, J. Sromicki, A. Strzalkowski, H. Witała, J. Zejma, W. Zipper
abstract
Proton induced deuteron breakup reaction at 65 MeV: Unspecific configurations
K. Bodek, W. Glockle, J. Golak, L. Jarczyk, S. Kistryn, B. Kozlowska, J. Lang, A. Micherdzinska, O. Naviliat-Cuncic, J. Smyrski, M. Sokolowski, J. Sromicki, A. Strzalkowski, H. Witala, J. Zejma, W. Zipper
abstract
Polarimetry of N-16(gs) produced in mu(-)-capture on O-16 nuclei
CP. Bee, D. Conti, M. Hadri, S. Kistryn, J. Lang, O. NaviliatCuncic, J. Sromicki, E. Stephan, K. Bodek, J. Smyrski, A. Strzalkowski, J. Zejma, L. Grenacs, R. Abela, P. Boni, F. Foroughi, W. Zipper, A. Proykova
abstract
A polarimetry technique based on stack targets and beta-gamma-coincidences has been applied to the N-16 nuclei produced in the ground state capture of negative muons on O-16 nuclei. The performance of the polarimeter and the first measurements of beta-asymmetry due to the longitudinal nuclear polarization are discussed.
Cross sections and analysing powers A(y) in the breakup reaction H-2((p)over-right-arrow,pp)n at 65 MeV: Star configurations
J. Zejma, M. Allet, K. Bodek, J. Lang, R. Muller, S. Navert, O. NaviliatCuncic, J. Sromicki, E. Stephan, L. Jarczyk, S. Kistryn, J. Smyrski, A. Strzalkowski, W. Glockle, J. Golak, D. Huber, H. Witała, PA. Schmelzbach
abstract
Cross-section and vector-analyzing-power data for three star configurations of the H-2((p) over right arrow,pp)n breakup reaction at E(p)(lab)=65 MeV were measured in a kinematically complete experiment. They are compared to rigorous Faddeev calculations involving five realistic charge-dependent nucleon-nucleon potentials: Argonne v(18), CD Bonn, Nijmegen 93, Nijmegen I, and Nijmegen II. A general satisfactory agreement between theory and experiment has been found. However, there exist also a few minor discrepancies in cross sections in some regions of phase space. The experimental data are compared also to the calculations including the (pi-pi) Tucson-Melbourne three-body force. Their effects are either negligible or increase the disagreement with the experiment.
Effects of the Tucson-Melbourne three-nucleon force in the proton-deuteron breakup process at E(p)=65 MeV
M. Allet, K. Bodek, J. Golak, W. Glockle, W. Hajdas, D. Huber, L. Jarczyk, H. Kamada, S. Kistryn, J. Lang, R. Muller, O. NaviliatCuncic, J. Smyrski, J. Sromicki, A. Strzalkowski, H. Witała, J. Zejma
abstract
We present the calculated cross sections and vector analyzing powers using the Bonn B nucleon-nucleon potential and the Tucson-Melbourne three-nucleon force (3NF) for six collinearity and quasi-free scattering breakup configurations. These calculations are compared to the results of the recent kinematically complete pd experiments at E(p) = 65 MeV. The Tucson-Melbourne 3NF, adjusted together with the Bonn B potential to reproduce the triton binding energy, leads to small effects both in cross sections and analyzing powers in all six studied configurations.
Proton-induced deuteron breakup at E(p)(lab)=65 MeV in quasi-free scattering configurations
M. Allet, K. Bodek, W. Hajdas, J. Lang, R. Muller, S. Navert, O. NaviliatCuncic, J. Sromicki, J. Zejma, L. Jarczyk, S. Kistryn, J. Smyrski, A. Strzalkowski, H. Witała, W. Glockle, J. Golak, D. Huber, H. Kamada
abstract
The proton-deuteron breakup cross sections and analyzing powers A(y) for three kinematically complete configurations in a quasi-free-scattering geometry have been measured at E(p)(lab) = 65 MeV. The data are compared with predictions of rigorous Faddeev calculations using the Argonne AV14, Bonn-B, Nijmegen-78, and Paris potentials. A satisfactory agreement between theory and experimental data, both for cross sections and analyzing powers, has been found.
Cross sections and vector analyzing powers in the proton induced deuteron breakup reaction at 65 MeV: Star configurations
M. Allet, K. Bodek, W. Glockle, J. Golak, L. Jarczyk, S. Kistryn, J. Lang, R. Muller, S. Navert, O. NaviliatCouncic, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, H. Witała, J. Zejma
abstract
Cross sections and vector analyzing powers in the proton induced deuteron breakup reaction at 65 MeV: Star configurations
M. Allet, K. Bodek, W. Glockle, J. Golak, L. Jarczyk, S. Kistryn, J. Lang, R. Muller, S. Navert, O. NaviliatCouncic, J. Smyrski, J. Sromicki, E. Stephan, A. Strzalkowski, H. Witala, J. Zejma
abstract
Proton-induced deuteron breakup at E(p)(lab)=65 MeV in quasi-free scattering configurations
M. Allet, K. Bodek, W. Hajdas, J. Lang, R. Muller, S. Navert, O. NaviliatCuncic, J. Sromicki, J. Zejma, L. Jarczyk, S. Kistryn, J. Smyrski, A. Strzalkowski, H. Witala, W. Glockle, J. Golak, D. Huber, H. Kamada
abstract
The proton-deuteron breakup cross sections and analyzing powers A(y) for three kinematically complete configurations in a quasi-free-scattering geometry have been measured at E(p)(lab) = 65 MeV. The data are compared with predictions of rigorous Faddeev calculations using the Argonne AV14, Bonn-B, Nijmegen-78, and Paris potentials. A satisfactory agreement between theory and experimental data, both for cross sections and analyzing powers, has been found.
