Rotational susceptibility of a hot and dense hadronic matter: A possible probe of QCD phase transition

TL;DR

This paper investigates how rotation affects a hot, dense hadronic matter produced in heavy ion collisions, proposing rotational susceptibilities as potential indicators of the QCD phase transition, including effects of interactions and particle spin.

Contribution

It introduces the first estimation of rotational susceptibilities in a hadron resonance gas, considering interactions, spin, and chemical potential effects, to probe the QCD phase transition.

Findings

Rotational susceptibilities are sensitive to the QCD phase transition.

Interactions between hadrons influence the phase transition signals.

Higher-order susceptibilities and their ratios provide detailed insights.

Abstract

We study the effect of rotation and the consequent angular momentum fluctuations in a hadron resonance gas produced in ultra-relativistic heavy ion collisions. The rotational susceptibilities ($\chi_{\rm \omega}$, $\chi^{2}_{\rm \omega}$, etc.), which quantify how much the system responds to a small angular velocity, are estimated for the first time, considering that these can be valuable indicators of the QCD phase transition. The higher-order rotational susceptibilities and their ratios are estimated in the presence and absence of baryon chemical potential ($\mu_{\rm B}$) in the system. The effect of particle spin ($s$) and rotational chemical potential ($\omega$) on the fluctuation of the angular momentum is studied. To consider a more realistic scenario, the effect of interactions between hadrons is taken into account by considering van der Waals-like interactions, which include both attractive and repulsive interactions. A phase transition, absent in an ideal hadron gas model, can be observed in an interacting hadron gas model.