On the energy dependence of $K/\pi$ fluctuations in relativistic heavy ion collisions

TL;DR

This paper investigates how the fluctuations in the kaon-to-pion ratio depend on collision energy in heavy ion experiments, showing consistency with multiplicity-based expectations across different experiments.

Contribution

It demonstrates that the energy dependence of $K/\pi$ fluctuations aligns with multiplicity effects, clarifying the underlying factors influencing these fluctuations in heavy ion collisions.

Findings

The excitation function of $K/\pi$ fluctuations matches multiplicity-based predictions.

Fluctuations are consistent with the expected dependence on accepted pions and kaons.

Results are validated across STAR and NA49 experimental data.

Abstract

In this note we will discuss the energy dependence of particle ratio fluctuations in heavy ion collisions. We study how the inherent multiplicity dependence of ratio fluctuations is reflected in the excitation function of the dynamical fluctuations. Specifically, we will show that the observed excitation function of dynamical $K/\pi$ fluctuations is consistent with the expected dependence on the number of accepted pions and kaons in both the STAR and NA49 experiments.