Charge Dependence and Scaling Properties of Dynamical $K/\pi$, $p/\pi$, and $K/p$ Fluctuations from the STAR Experiment

TL;DR

This paper reports on measurements of charge-dependent dynamical fluctuations in heavy-ion collisions across various energies, aiming to identify signals of the QCD critical point and compare with theoretical models.

Contribution

It provides new energy-dependent measurements of $K/\pi$, $p/\pi$, and $K/p$ fluctuations using $ u_{ m dyn}$, and evaluates scaling scenarios to relate experimental data to thermodynamic predictions.

Findings

Energy dependence observed in fluctuation measurements.

Scaling scenarios tested for volume independence.

Comparison with theoretical models highlights potential critical point signals.

Abstract

Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be enhanced near a QCD critical point. Charge dependent results from new measurements of dynamical $K/\pi$, $p/\pi$, and $K/p$ ratio fluctuations are presented. The STAR experiment has performed a comprehensive study of the energy dependence of these dynamical fluctuations in Au+Au collisions at the energies $\sqrt{s_{NN}}$ = 7.7-200 GeV using the observable, $\nu_{\rm dyn}$. These results are compared to previous measurements and to theoretical predictions. Various proposed scaling scenarios that attempt to remove the intrinsic volume dependence of $\nu_{\rm dyn}$ and to simplify comparisons between experimental measurements are also considered. Constructing an intensive quantity allows for a direct connection to thermodynamic predictions.