512 research outputs found
The of the LQCD-EoS complied hadron gas of different sizes approach common minimum near the crossover temperature
We study the temperature dependence of the ratio of the shear viscosity to
entropy density for the LQCD-contrasted hadron resonance gas of different
finite system-sizes, which may represent the final state hadronic matter,
formed in systems of ultra-relativistic collisions. The transport coefficient
reaches the lowest common value, for the systems of different sizes of
thermalized hadron gas, near the critical temperature of the QCD
crossover.Comment: 6 pages 6 figures. To appear in EPJ
Indication of transverse radial flow in high-multiplicity proton-proton collisions at the Large Hadron Collider
We analyze the measured spectra of , , () in
collisions at = 0.9, 2.76 and 7 TeV, in the light of blast-wave
model to extract the transverse radial flow velocity and kinetic temperature at
freeze-out for the system formed in collisions. The dependency of the
blast-wave parameters on average charged particle multiplicity of event sample
or the `centrality' of collisions has been studied and compared with results of
similar analysis in nucleus-nucleus () and proton-nucleus ()
collisions. We analyze the spectra of , () and
also to see the dependence of blast-wave description on the species of
produced particles. Within the framework of the blast-wave model, the study
reveals indication of collective behavior for high-multiplicity events in
collisions at LHC. Strong transverse radial flow in high multiplicity
collisions and its comparison with that in and collisions match with
predictions from a very recent theoretical work [Shuryak and Zahed 2013
arXiv:1301.4470] that addresses the conditions for applicability of
hydrodynamics in and collisions.Comment: 14 pages 8 figure
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