Trapped Antihydrogen in Its Ground State
G. Gabrielse, R. Kalra, W. S. Kolthammer, R. McConnell, P. Richerme, D. Grzonka, W. Oelert, T. Sefzick, M. Zieliński, D. W. Fitzakerley, M. C. George, E. A. Hessels, C. H. Storry, M. Weel, A. Müllers, J. Walz
abstract
Antihydrogen atoms are confined in an Ioffe trap for 15 to 1000 seconds -- long enough to ensure that they reach their ground state. Though reproducibility challenges remain in making large numbers of cold antiprotons and positrons interact, 5 +/- 1 simultaneously-confined ground state atoms are produced and observed on average, substantially more than previously reported. Increases in the number of simultaneously trapped antithydrogen atoms are critical if laser-cooling of trapped antihydrogen is to be demonstrated, and spectroscopic studies at interesting levels of precision are to be carried out.
From mesons to tomography
P. Moskal
published in: Magazyn Kompas Innowacji nr 4
Revealing Bells nonlocality for unstable systems in high energy physics
B. C. Hiesmayr, A. Di Domenico, C. Curceanu, A. Gabriel, M. Huber, J-A Larsson, P. Moskal
abstract
Entanglement and its consequences?in particular
the violation of Bell inequalities, which defies our concepts
of realism and locality?have been proven to play
key roles in Nature by many experiments for various quantum
systems. Entanglement can also be found in systems
not consisting of ordinary matter and light, i.e. in massive
meson?antimeson systems. Bell inequalities have been discussed
for these systems, but up to date no direct experimental
test to conclusively exclude local realism was found.
This mainly stems from the fact that one only has access to
a restricted class of observables and that these systems are
also decaying. In this Letter we put forward a Bell inequality
for unstable systems which can be tested at accelerator facilities
with current technology. Herewith, the long awaited
proof that such systems at different energy scales can reveal
the sophisticated dynamical nonlocal feature of Nature in
a direct experiment gets feasible. Moreover, the role of entanglement
and CP violation, an asymmetry between matter
and antimatter, is explored, a special feature offered only by
these meson?antimeson systems.
Abashian-Booth-Crowe effect in basic double fusion: A new resonance?
WASA-at-COSY Collaboration: P. Adlarson, ..., T. Bednarski, E. Czerwiński, M. Hodana, J. Klaja, W. Krzemień, P. Moskal, S. Niedzwiecki, M. Skurzok, M. Zieliński, 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.
Adiabatic Cooling of Antiprotons
G. Gabrielse, W. S. Kolthammer, R. McConell, P. Richerme, R. Kalra, E. Novitski, D. Grzonka, W. Oelert, T. Sefzick,M. Zieliński, D. Fitzakerley, M. C. George, E. A. Hassels, C. H. Storry, M. Weel, A. Müllers, J. Walz
abstract
Adiabatic cooling is shown to be a simple and effective method to cool many charged particles in a trap to very low temperatures. Up to 3×106 antiprotons are cooled to 3.5 K - 10^3 times more cold antiprotons and a 3 times lower antiproton temperature than previously reported. A second cooling method cools antiproton plasmas via the synchrotron radiation of embedded e- (with many fewer e- than antiproton ) in preparation for adiabatic cooling. No antiprotons are lost during either process - a significant advantage for rare particles.
Centrifugal separation of antiprotons and electrons
G. Gabrielse, W. S. Kolthammer, R. McConell, P. Richerme, J. Wrubel, R. Kalra, E. Novitski, D. Grzonka, W. Oelert, T. Sefzick, M. Zieliński, J. S. Borbely, D. Fitzakerley, M. C. George, E. A. Hassels, C. H. Storry, M. Weel, A. Müllers, J. Walz, A. Speck
abstract
Centrifugal separation of antiprotons and electrons is observed, the first such demonstration with particles that cannot be laser cooled or optically imaged. The spatial separation takes place during the electron cooling of trapped antiprotons, the only method available to produce cryogenic antiprotons for precision tests of fundamental symmetries and for cold antihydrogen studies. The centrifugal separation suggests a new approach for isolating low energy antiprotons and for producing a controlled mixture of antiprotons and electrons.
Determination of the total width of the eta-prime meson
E. Czerwiński, P. Moskal, D. Grzonka, R. Czyżykiewicz, D. Gil, B. Kamys, A. Khoukaz, J. Klaja, P. Klaja, W. Krzemień, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, M. Silarski, J. Smyrski, A. Täschner, M. Wolke, P. Wüstner, J. Zdebik, M. Zieliński, W. Zipper
abstract
Taking advantage of both the low-emittance proton beam of the cooler synchrotron COSY and the high momentum precision of the COSY-11 detector system, the mass distribution of the eta-prime meson was measured with a resolution of 0.33??MeV/c2 (FWHM), improving the experimental mass resolution by almost an order of magnitude with respect to previous results. Based on the sample of more than 2300 reconstructed pp->pp eta-prime events, the total width of the eta-prime meson was determined to be Gamma(eta-prime) = 0.226+-0.017(stat)+-0.014(syst)??MeV/c2.
Physics of more than 11 years of COSY-11 - history, status, achievements, plans.
J. Przerwa, D. Grzonka, P. Klaja, P. Moskal, W. Oelert (Eds.)
published in: Schriften des Forschungszentrums Jülich, Reihe Materie und Material / Matter and Materials, Band /Volume 36, ISSN 1433-5522, ISB
Mechanism of the close-to-threshold production of the eta meson.
R. Czyzykiewicz, P. Moskal, H. -H. Adam, A. Budzanowski, E. Czerwinski, D. Gil, D. Grzonka, M. Hodana, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz, K. Kilian, P. Klaja, B. Lorentz, W. Oelert, C. Piskor-Ignatowicz, J. Przerwa, B. Rejdych, J. Ritman, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taeschner, K. Ulbrich, P. Winter, M. Wolke, P. Wuestner, W. Zipper
abstract
Measurements of the analysing power for the p(pol)p --> ppeta reaction have been performed in the close-to-threshold energy region at beam momenta of p_{beam}=2.010 and 2.085 GeV/c, corresponding to excess energies of Q=10 and 36 MeV, respectively. The determined analysing power is essentially consistent with zero implying that the eta meson is produced predominantly in the s-wave at both excess energies. The angular dependence of the analysing power, combined with the hitherto determined isospin dependence of the total cross section for the eta meson production in nucleon-nucleon collisions, reveal a statistically significant indication that the excitation of the nucleon to the S_{11}(1535) resonance, the process which intermediates the production of the eta meson, is predominantly due to the exchange of the pi meson between the colliding nucleons.
Comparison of Lambda and Sigma 0 Production near Threshold in Proton-Proton Collisions
S. Sewerin, ..., A. Budzanowski, W. Eyrich, C. Goodman, D. Grzonka, L. Jarczyk, K. Kilian, P. Moskal, J. Smyrski et al.
abstract
Threshold measurements of the associated strangeness production reactions pp->pK1L and
pp-> pK1S0 are presented. The most remarkable feature of the data is that at the same excess
energy the total cross section for the S0 production appears to be about a factor of 2816
29 smaller
than for the L particle. It is concluded that strong S0p final state interactions, and in particular the
SN ! Lp conversion reaction, are the likely cause of the depletion in the S signal. This hypothesis
is in line with other experimental evidence in the literature.
Eta-prime production in proton proton scattering close to threshold.
P. Moskal, ..., J. T. Balewski, A. Budzanowski, H. Dombrowski, C. Goodman, D. Grzonka, J. Haidenbauer et al.
abstract
The pp-->ppeta-prime reaction has been measured at the cooler synchrotron COSY at Jülich using the internal beam and the COSY-11 facility. The total cross sections at the four different excess energies Q = 1.5,1.7,2.9, and 4.1 MeV have been evaluated to be sigma = 2.5+-0.5,2.9+-1.1,12.7+-3.2, and 25.2+-3.6nb, respectively. In this region of excess energy the eta-prime cross sections are much lower compared to those of the pi0 and eta production.
