Non-Gaussian fluctuations near the QCD critical point

TL;DR

This paper investigates how the QCD critical point influences non-Gaussian fluctuation moments in heavy-ion collisions, revealing high sensitivity of these moments to the correlation length and estimating their magnitudes.

Contribution

It provides a quantitative analysis of non-Gaussian moments' dependence on the critical point and estimates their size for pion and proton fluctuations.

Findings

Non-Gaussian moments are highly sensitive to the correlation length near the critical point.

Cubic moments scale as xi^4.5, quartic cumulants as xi^7.

Estimated critical point effects on pion and proton fluctuations are significant.

Abstract

We study the effect of the QCD critical point on non-Gaussian moments (cumulants) of fluctuations of experimental observables in heavy-ion collisions. We find that these moments are very sensitive to the proximity of the critical point, as measured by the magnitude of the correlation length xi. For example, the cubic central moment of multiplicity ~ xi^4.5 and the quartic cumulant ~ xi^7. We estimate the magnitude of critical point contributions to non-Gaussian fluctuations of pion and proton multiplicities.