Importance of repulsive interactions for the equation of state and other properties of strongly interacting matter

TL;DR

This paper emphasizes the crucial role of repulsive interactions in the equation of state of strongly interacting matter, affecting phase transition characteristics and particle density distributions in hadron and quark-gluon systems.

Contribution

It demonstrates how particle size and repulsive forces influence phase transition types and the properties of strongly interacting matter in hadron-resonance gases and quark-gluon bags.

Findings

Repulsive interactions significantly alter net-baryon density maxima.

The transition point depends on baryon and meson radii differences.

Various phase transition types can be realized depending on quark-gluon bag properties.

Abstract

We illustrate the role of repulsive interactions in a hadron-resonance gas at freeze-out and in a gas of quark-gluon bags. Taking into account non-zero size of particles in hadron gas leads to a significant decrease and shift of the net-baryon density maximum. The transition point from baryon to meson dominated matter depends on the difference between baryon and meson radii. We also show that depending on the properties of the quark-gluon bags one may obtain any type of the phase transition from hadron gas to quark-gluon plasma: the first or second order, as well as four types of the crossover.