Determination of freeze-out conditions from fluctuations in the Hadron Resonance Gas model

[摘要] Fluctuations of conserved charges measured in Heavy-Ion Collisions (HICs) received increasing attention in recent years, because they are good candidates to explore the phase diagram of QCD matter. During the last year, net-electric charge and net-proton moments of multiplicities measured at RHIC have been published by the STAR collaboration, for a range of collision energies which spans a region of the phase diagram at finite chemical potential. Here we present a new freeze-out curve obtained using the Hadron Resonance Gas (HRG) model approach to fit these experimental data. The HRG model is modified in order to have a realistic description of the HICs: kinematic cuts, resonance feed-down and resonance regeneration are taken into account. Our result is in agreement with preliminary studies by the ALICE collaboration, and is supported by a recent lattice analysis of the same quantities.

[发布机构] Department of Physics, Torino University and INFN, Sezione di Torino, via P. Giuria 1, Torino; 10125, Italy^1;Department of Physics, University of Houston, Houston; TX; 77204, United States^2;Department of Physics, North Carolina State University, Raleigh; NC; 27695, United States^3;Department of Physics, Duke University, Durham; NC; 27708-305, United States^4

[关键词] Collision energies;Freeze out;Hadron resonance gas;Heavy ion collision;Lattice analysis;Model approach