Higher moment singularities explored by the net proton non-statistical fluctuations

TL;DR

This study investigates higher moment singularities in net proton fluctuations in relativistic Au+Au collisions using non-statistical moments, revealing a potential singularity around 60 GeV.

Contribution

It introduces the use of non-statistical moments to identify singularities in net proton fluctuation data, providing new insights into collision dynamics.

Findings

Consistent results with STAR data for mean, variance, skewness, kurtosis

Evidence of a singularity at approximately 60 GeV in non-statistical moments

First observation of such singularity in energy-dependent non-statistical skewness and kurtosis.

Abstract

We use the non-statistical fluctuation instead of the full one to explore the higher moment singularities of net proton event distributions in the relativistic Au+Au collisions at $\sqrt{s_{NN}}$ from 11.5 to 200 GeV calculated by the parton and hadron cascade model PACIAE. The PACIAE results of mean ($M$), variance ($\sigma^2$), skewness ($S$), and kurtosis ($\kappa$) are consistent with the corresponding STAR data. Non-statistical moments are calculated as the difference between the moments derived from real events and the ones from mixed events, which are constructed by combining particles randomly selected from different real events. An evidence of singularity at $\sqrt{s_{NN}}\sim$ 60 GeV is first seen in the energy dependent non-statistical $S$ and $S\sigma$.