Statistical and dynamical fluctuations in the ratios of higher cumulants in relativistic heavy ion collisions

TL;DR

This paper investigates the fluctuations in higher cumulant ratios of net-protons in heavy ion collisions, emphasizing the dominance of statistical fluctuations and the importance of dynamical fluctuations for understanding particle production mechanisms.

Contribution

It highlights the dominance of statistical fluctuations in measured cumulant ratios and proposes that future measurements focus on dynamical fluctuations to explore underlying physics.

Findings

Statistical fluctuations dominate the measured cumulant ratios.

Proton-antiproton correlations indicate independent emission.

Dynamical fluctuations are key to understanding critical phenomena.

Abstract

With the help of transport and statistical models, we find that the ratios of higher net-proton cumulants measured at RHIC are dominated by the statistical fluctuations. Future measurements should focus on the dynamical fluctuations, which are relevant to the underlying mechanisms of particle production, the critical phenomena in particular. We also demonstrate that a proton-antiproton correlation directly show if protons and antiprotons are emitted independently.