New scenarios for hard-core interactions in a hadron resonance gas

Understand

The equation of state of a baryon-symmetric hadronic matter with hard-sphere interactions is studied.

• It is assumed that mesons are point-like, but baryons and antibaryons have the same hard-core radius rB.
• Three possibilities are considered: 1) the baryon-baryon and antibaryon-baryon interactions are the same; 2) baryons do not interact with antibaryons; 3) the baryon-antibaryon and meson-(anti)baryon interactions are negligible.
• By choosing the parameter rB=0.3-0.6 fm, we calculate the nucleon to pion ratio as a function of temperature and perform the fit of hadron yields measured in central Pb+Pb collisions at the bombarding energy Ecm=2.76 TeV per nucleon pair.