Energy Dependence of Intermittency for Charged Hadrons in Au+Au Collisions at RHIC

TL;DR

This study measures intermittency in charged hadrons from Au+Au collisions at RHIC energies, revealing energy-dependent fluctuations that may relate to the QCD critical point.

Contribution

First measurement of intermittency in Au+Au collisions across a wide energy range at RHIC, analyzing scaled factorial moments to explore QCD phase structure.

Findings

Power-law behavior of factorial moments observed

Scaling exponent decreases from peripheral to central collisions

Non-monotonic energy dependence of exponent with a minimum around 27 GeV

Abstract

Density fluctuations near the QCD critical point can be probed via an intermittency analysis in relativistic heavy-ion collisions. We report the first measurement of intermittency in Au$+$Au collisions at $\sqrt{s_\mathrm{_{NN}}}$ = 7.7-200 GeV measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The scaled factorial moments of identified charged hadrons are analyzed at mid-rapidity and within the transverse momentum phase space. We observe a power-law behavior of scaled factorial moments in Au$+$Au collisions and a decrease in the extracted scaling exponent ($\nu$) from peripheral to central collisions. The $\nu$ is consistent with a constant for different collisions energies in the mid-central (10-40\%) collisions. Moreover, the $\nu$ in the 0-5\% most central Au$+$Au collisions exhibits a non-monotonic energy dependence that reaches a possible minimum around $\sqrt{s_\mathrm{_{NN}}}$ = 27 GeV. The physics implications on the QCD phase structure are discussed.