2016/09/30 by Volodymyr Vovchenko, Mark I. Gorenstein, Horst Stoecker · 1 citation
Physics and Astronomy · #hep-ph #hep-lat #nucl-th
paper · pdf · doi:10.1103/physrevlett.118.182301
published as Phys. Rev. Lett. 118, 182301 (2017) · 7 pages, 3 figures, final version published in Physical Review Letters, minor misprints corrected
arxiv created 2017/05/18 · arxiv updated 2017/05/22
An extension of the ideal hadron resonance gas (HRG) model is constructed which includes the attractive and repulsive van der Waals (VDW) interactions between baryons. This VDW-HRG model yields the nuclear liquid-gas transition at low temperatures and high baryon densities. The VDW parameters a and b are fixed by the ground state properties of nuclear matter, and the temperature dependence of various thermodynamic observables at zero chemical potential are calculated within VDW-HRG model. Compared to the ideal HRG model, the inclusion of VDW interactions between baryons leads to a qualitatively different behavior of second and higher moments of fluctuations of conserved charges, in particular in the so-called crossover region T∼ 140 - 190 MeV. For many observables this behavior resembles closely the results obtained from lattice QCD simulations. This hadronic model also predicts nontrivial behavior of net-baryon fluctuations in the region of phase diagram probed by heavy-ion collision experiments. These results imply that VDW interactions play a crucial role in thermodynamics of hadron gas. Thus, the commonly performed comparisons of the ideal HRG model with the lattice and heavy-ion data may lead to misconceptions and misleading conclusions.