Can charm fluctuation be a better probe to study QCD critical point?

TL;DR

This paper investigates the diffusion properties of a hadron gas, including charm quarks, and suggests charm fluctuations could be a more effective probe for identifying the QCD critical point.

Contribution

It introduces the first estimation of charm diffusion coefficients in a hadron gas, incorporating charm as part of the medium and analyzing its implications for QCD critical point detection.

Findings

Charm diffusion coefficients depend on temperature and energy.

Good agreement with existing models in the hadronic limit.

Charm fluctuations may serve as better probes for the QCD critical point.

Abstract

We study the diffusion properties of an interacting hadron gas and evaluate the diffusion coefficient matrix for the baryon, strange, electric, and charm quantum numbers. For the first time, this study sheds light on the charm current and estimates the diffusion matrix coefficient for the charmed states by treating them as a part of the quasi-thermalized medium. We explore the diffusion matrix coefficient as a function of temperature and center-of-mass energy. A van der Waals-like interaction is assumed between the hadrons, including attractive and repulsive interactions. The calculation of diffusion coefficients is based on relaxation time approximation to the Boltzmann transport equation. A good agreement with available model calculations is observed in the hadronic limit. To conclude the study, we discuss, with a detailed explanation, that charm fluctuation is expected to be a better tool for probing the QCD critical point.