Higher Moments of Net-Kaon Multiplicity Distributions at STAR

TL;DR

This paper measures higher moments of net-kaon multiplicity distributions in heavy-ion collisions at various energies to search for signs of the QCD critical point, comparing results with baseline and non-critical models.

Contribution

It provides the first comprehensive analysis of efficiency-corrected cumulants and their ratios for net-kaons across multiple energies and centralities in STAR data.

Findings

Cumulant ratios vary with collision energy and centrality.

Results are compared with Poisson and UrQMD models.

Data show potential deviations from non-critical models near certain energies.

Abstract

Fluctuations of conserved quantities such as baryon number (B), electric charge number (Q), and strangeness number (S), are sensitive to the correlation length and can be used to probe non-gaussian fluctuations near the critical point. Experimentally, higher moments of the multiplicity distributions have been used to search for the QCD critical point in heavy-ion collisions. In this paper, we report the efficiency-corrected cumulants and their ratios of mid- rapidity (|y| < 0.5) net-kaon multiplicity distributions in Au+Au collisions at 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV collected in 2010, 2011, and 2014 with STAR at RHIC. The centrality and energy dependence of the cumulants and their ratios, are presented. Furthermore, the comparisons with baseline calculations (Poisson) and non-critical-point models (UrQMD) are also discussed.