Partial pressure and susceptibilities of charmed sector in the van der Waals hadron resonance gas model

TL;DR

This paper enhances the understanding of charm sector susceptibilities by employing the van der Waals hadron resonance gas model, which accounts for both attractive and repulsive interactions, improving agreement with lattice QCD data at high temperatures.

Contribution

The study introduces the VDWHRG model for charm susceptibilities, demonstrating its superiority over ideal and excluded volume models in matching lattice QCD results at high temperatures.

Findings

VDWHRG model aligns well with lattice QCD data up to 180 MeV.

Including both attractive and repulsive interactions improves modeling accuracy.

Charm susceptibility ratios are effectively estimated in baryon-rich environments.

Abstract

We investigate the general susceptibilities in the charm sector by using the van der Waals hadron resonance gas model (VDWHRG). We argue that the ideal hadron resonance gas (HRG), which assumes no interactions between hadrons, and the excluded volume hadron resonance gas (EVHRG), which includes only repulsive interactions, fail to explain the lQCD data at very high temperatures. In contrast, the VDWHRG model, incorporating both attractive and repulsive interactions, extends the degree of agreement with lQCD up to nearly 180 MeV. We estimate the partial pressure in the charm sector and study charm susceptibility ratios in a baryon-rich environment, which is tricky for lattice quantum chromodynamics (lQCD) due to the fermion sign problem. Our study further solidifies the notion that the hadrons shouldn't be treated as non-interacting particles, especially when studying higher order fluctuations, but rather one should consider both attractive and repulsive interactions between the hadrons.