Study of Dynamical $K/\pi$ and $p/\pi$ Fluctuations in $\sqrt{s_{NN}}$ = 22.4 GeV Cu+Cu Collisions from the STAR Experiment

TL;DR

This paper reports the first measurement of dynamical $K/\pi$ and $p/\pi$ ratio fluctuations in Cu+Cu collisions at 22.4 GeV, providing insights into QCD critical point search and comparing with previous data and models.

Contribution

It presents the first results of $K/\pi$ and $p/\pi$ fluctuations in Cu+Cu collisions at 22.4 GeV and compares them with prior experiments and theoretical models.

Findings

Dynamical $K/\pi$ fluctuations agree with previous measurements near that energy.

Results are consistent with NA49 and STAR data at similar energies.

Model comparisons show compatibility with HIJING and UrQMD predictions.

Abstract

Results from the measurement of dynamical $K/\pi$ and $p/\pi$ ratio fluctuations are presented. Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. The first measurement of results of $K/\pi$ and $p/\pi$ fluctuations from Cu+Cu collisions at an energy $\sqrt{s_{NN}}$ = 22.4 GeV are shown. This energy range is close to the top SPS energy and has garnered additional interest due to the proposed QCD critical point search at RHIC. The new Cu+Cu data is compared to previous results from Au+Au collisions at the energies $\sqrt{s_{NN}}$ = 19.6, 62.4, 130, and 200 GeV, and to measurements from the NA49 experiment. The dynamical $K/\pi$ fluctuation results from Cu+Cu at $\sqrt{s_{NN}}$ = 22.4 GeV are in good agreement with previous measurements from the STAR and NA49 experiments near that energy. Results are compared to theoretical predictions from several models including the HIJING and UrQMD models.