**The cosmological constant and Higgs mass with emergent gauge symmetries**

*S.D. Bass, J. Krzysiak*

abstract

We discuss the Higgs mass and cosmological constant in the context of an emergent Standard Model, where the gauge symmetries dissolve in the extreme ultraviolet. In this scenario the cosmological constant scale is suppressed by power of the large scale of emergence and expected to be of similar size to neutrino masses. Cosmology constraints then give an anthropic upper bound on the Higgs mass.

**Study of the N* momentum distribution for experimental eta-mesic 3He searches**

*N. G. Kelkar, D. Bedoya Fierro, H. Kamada, M. Skurzok*

abstract

The proximity of the etaN threshold to the mass of the N*(1535) allows us to consider the eta-nucleus interaction below the eta threshold as a series of excitations, decays of the N* on the constituent nucleons and the eventual decay of the N* to a nucleon and a pion. Experimental searches for eta-mesic nuclei rely on this model in their analysis of data where an eta-mesic nucleus could have been formed. However, the momentum distribution of an N* is often approximated to be the same as that of a nucleon inside the nucleus. Our aim is to obtain an estimate of the error introduced by this assumption and hence we calculate the momentum distribution of the N* formed inside 3He. This distribution is found to be narrower than that of a nucleon inside 3He. The latter affects the outgoing particles kinematics and reduces the determined acceptance of their experimental registration by the detection setup. This reduction is crucial for the determination of cross sections in the search for eta-mesic helium.

**Emergent Gauge Symmetries and Particle Physics**

*S.D. Bass*

abstract

Hadron properties and interactions are emergent from QCD. Atomic and condensed matter physics are emergent from QED. Could the local gauge symmetries of particle physics also be emergent? We give an introduction to this question and recent ideas connecting it to the (meta)stability of the Standard Model Higgs vacuum. With an emergent Standard Model the gauge symmetries would dissolve in the ultraviolet. This scenario differs from unification models which exhibit maximum symmetry in the extreme ultraviolet. With emergence, new global symmetry violations would appear in higher dimensional operators.

**Vacuum energy with mass generation and Higgs bosons**

*S.D. Bass, J. Krzysiak*

abstract

We discuss the Higgs mass and cosmological constant hierarchy puzzles with emphasis on the interplay of Poincare invariance, mass generation and renormalization group invariance. A plausible explanation involves an emergent Standard Model with the cosmological constant scale suppressed by power of the large scale of emergence. In this scenario the cosmological constant scale and neutrino masses should be of similar size.

**N-N-N* model calculations for experimental eta-mesic 3He searches**

*N. G. Kelkar, H. Kamada, M. Skurzok*

abstract

The possibility for the existence of the exotic NNN* states is explored with the objective of calculating the N* momentum distribution inside such nuclei. Even though the latter is an essential ingredient for the analysis of the experimental data on the pd->pdpi0, pd->ppppi- and pd->pnnpi+ reactions aimed at finding an eta-mesic 3He, the data analysis is usually performed by approximating the N* momentum distribution by that of a nucleon. Here, we present calculations performed by solving the three-body Faddeev equations to obtain the momentum distribution of the N* inside possible (N* )+np, (N* )0np and (N* )+-d states. The N*
momentum distributions are found to be much narrower than those of the nucleons and influence the data selection criteria.

**Witnessing Entanglement In Compton Scattering Processes Via Mutually Unbiased Bases**

*Beatrix C. Hiesmayr, Pawel Moskal*

abstract

We present a quantum information theoretic version of the Klein-Nishina formula. This formulation singles out the quantity, the a priori visibility, that quantifies the ability to deduce the polarisation property of single photons. The Kraus-type structure allows a straightforward generalisation to the multiphoton cases, relevant in the decay of positronium which is utilized e.g. for metabolic PET-imaging (Positron-Emission-Tomograph). Predicted by theory but never experimentally proven, the two- or three-photon states should be entangled. We provide an experimentally feasible method to witness entanglement for these processes via MUBs (Mutually Unbiased Bases), exploiting Bohr?s complementarity. Last but not least we present explicit cases exemplifying the interrelation of geometry and entanglement including relations to its potentiality for teleportation schemes or Bell inequality violations or in future for detecting cancer in human beings.

**Etaprime and Eta Mesons with Connection to Anomalous Glue**

*S. D. Bass, P. Moskal*

abstract

We review the present understanding of etaprime and eta meson physics and these mesons as a probe of gluon dynamics in low-energy QCD. Recent highlights include the production mechanism of eta and etaprime mesons in proton-nucleon collisions from threshold to high-energy, the etaprime effective mass shift in the nuclear medium, searches for possible eta and etaprime bound states in nuclei as well as precision measurements of eta decays as a probe of light-quark masses. We discuss recent experimental data, theoretical interpretation of the different measurements and the open questions and challenges for future investigation.

**QED and Fundamental Symmetries in Positronium Decays**

*Steven D. Bass*

abstract

We discuss positronium decays with emphasis on tests of fundamental symmetries and the constraints from measurements of other precision observables involving electrons and photons.

**Updating spin-dependent Regge intercepts**

*S. D. Bass, M. Skurzok, P. Moskal *

abstract

We use new high statistics data from CLAS and COMPASS on the nucleon's spin structure function at low Bjorken x and low virtuality, Q^2 < 0.5 GeV^2, together with earlier measurements from the SLAC E-143, HERMES and GDH experiments to estimate the effective intercept(s) for spin dependent Regge theory. We find alpha_{a_1} = 0.31 pm 0.04 for the intercept describing the high-energy behaviour of spin dependent photoabsorption together with a new estimate for the high-energy part of the Gerasimov-Drell-Hearn sum-rule, -15 pm 2 mu b from photon-proton centre-of-mass energy greater than 2.5 GeV. Our value of alpha_{a_1} suggests QCD physics beyond a simple straight-line a_1 trajectory.

**Emergence in Particle Physics**

*S.D. Bass*

abstract

Hadron properties and interactions are emergent from QCD. Atomic and condensed matter physics are emergent from QED. Could the local gauge symmetries of particle physics also be emergent? We give an introduction to this question and recent ideas connecting it to the stability of the Standard Model Higgs vacuum and the value of the cosmological constant.

**Genuine Multipartite Entanglement in the 3-Photon Decay of Positronium**

*B.C. Hiesmayr, P. Moskal*

abstract

**Spinning Gluons in the Proton**

*S.D. Bass*

abstract

Computer simulations indicate that about 50% of the proton?s spin comes from the spin of the gluons that bind its quark constituents.

**eta' Interactions with Nucleons and Nuclei**

*S. D. Bass, P. Moskal*

abstract

We summarise recent progress in theory and experiment towards understanding of ??-meson interactions with nucleons and nuclei. Highlights include the production mechanism of ?? mesons in proton?proton collisions close to the threshold, the ?? effective mass shift in nuclei and the determination of the ??-nucleon scattering length in free space.

**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.