6297638
Isospin tracing: A probe of nonequilibrium in central heavy-Ion collisions
Four different combinations of 9644Ru and 9640Zr nuclei, both as projectile and target, were investigated at the same bombarding energy of 400A MeV using a 4pi detector. The degree of isospin mixing between projectile and target nucleons is mapped across a large portion of the phase space using two different isospin-tracer observables, the number of measured protons and the tritium to 3He yield ratio. The experimental results show that the global equilibrium is not reached even in the most central collisions. Quantitative measures of stopping and mixing are extracted from the data. They are found to exhibit a quite strong sensitivity to the in-medium ( n,n) cross section used in microscopic transport calculations.
125217497
Use of open charm production for the in-medium effect in nuclear collisions at the future GSI facility
16672852
Quantitative aging study with intense irradiation tests for the CMS forward RPCs
Abstract A systematic study with a series of irradiation tests was performed for the forward resistive plate chambers (RPCs) of the Compact Muon Solenoid (CMS) in the Large Hadron Collider (LHC) experiment. Small double-gap RPCs were manufactured and tested by the gamma rays emitted from a 200 mCi 137 Cs source at Korea University and by the fast neutrons provided by the MC50 proton cyclotron at the Korea Institute Radiological and Medical Science (KIRAMS). We found no significant symptom of aging in the performance of the prototype RPCs, as a consequence of the neutron irradiation, whose total equivalent dose was approximately 45 Gy. However, a fast degradation was observed in the RPCs when the gamma signal rates were higher than 3 kHz cm − 2 . Furthermore, we observed from the chemical analysis for the RPC electrode that the long-term performance of the RPCs was stable in spite of absorbing the high-level fluorine when the signal rates were lower than 2 kHz cm − 2 .
73535789
Two-proton small-angle correlations in central heavy-ion collisions: A beam-energy- and system-size-dependent study
Abstract.Small-angle correlations of pairs of protons emitted in central collisions of Ca + Ca, Ru + Ru and Au + Au at beam energies from 400 to 1500MeV per nucleon are investigated with the FOPI detector system at SIS/GSI Darmstadt. Dependences on system size and beam energy are presented which extend the experimental data basis of pp correlations in the SIS energy range substantially. The size of the proton-emitting source is estimated by comparing the experimental data with the output of a final-state interaction model which utilizes either static Gaussian sources or the one-body phase-space distribution of protons provided by the BUU transport approach. The trends in the experimental data, i.e. system size and beam energy dependences, are well reproduced by this hybrid model. However, the pp correlation function is found rather insensitive to the stiffness of the equation of state entering the transport model calculations.
122486144
Strangeness and In-Medium Effects in Relativistic Nucleus-Nucleus Collisions at SIS Energies
122790056
Results from FOPI on strangeness in nuclear matter at SIS energies
Experimental data on charged kaon phase space distributions and strangeness sideward flow measured with the FOPI detector at SIS/GSI are presented. Comparisons are made with the predictions of transport models investigating the in-medium kaon-nucleon potential.
34981921
Dynamical mass generation in (2+1)-dimensional QED with a Chern-Simons term.
We analyze the effect of a Chern-Simons term in the dynamical generation of masses for fermions in (2+1)-dimensional QED in the large-flavor ([ital N]) limit. When a Chern-Simons term is present, both the magnitude and the critical flavor number for the parity-even (four-component) mass are reduced.