Universal relations between nongaussian fluctuations in heavy-ion collisions

TL;DR

This paper demonstrates that near a critical end point in heavy-ion collisions, universal relations between third- and fourth-order baryon susceptibilities produce distinctive banana-shaped loops, aiding the identification of critical phenomena.

Contribution

It establishes a universal relation between baryon susceptibilities and predicts a characteristic loop pattern as a signature of criticality in heavy-ion collision data.

Findings

A banana-shaped loop in susceptibility plots near the critical point.

Universal relation between third- and fourth-order baryon susceptibilities.

Potential observational signature of critical behavior in baryon fluctuations.

Abstract

We show that universality near a critical end point implies a characteristic relation between third- and fourth-order baryon susceptibilities $\chi_3$ and $\chi_4$, resulting in a banana-shaped loop when $\chi_4$ is plotted as a function of $\chi_3$ along a freeze-out line. Including the individual enhancements of $\chi_3$ and $\chi_4$ near a critical point, these features may be a consistent set of observations supporting the interpretation of baryon fluctuations data as arising from criticality.