Search for the critical point of strongly interacting matter

TL;DR

This paper reports on a systematic experimental search for the QCD critical point by analyzing fluctuations in particle multiplicity across different collision energies and system sizes, aiming to identify non-monotonic behaviors indicative of critical phenomena.

Contribution

It introduces a comprehensive analysis of fluctuation observables in heavy-ion collisions to locate the QCD critical point, utilizing extensive data from NA61/SHINE.

Findings

No definitive non-monotonic signals observed

Systematic variation of fluctuation measures with energy and system size

Enhanced fluctuations in specific collision conditions

Abstract

The existence and location of the QCD critical point is an object of both experimental and theoretical studies. The comprehensive data collected by NA61/SHINE during a two-dimensional scan in beam momentum (13A-150A GeV/c) and system size (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La, Pb+Pb) allows for a systematic search for the critical point-a search for a non-monotonic dependence of various correlation and fluctuation observables on collision energy and size of colliding nuclei. In particular, fluctuations of particle number in transverse momentum space are studied. They are quantified by measuring the scaled factorial moments of multiplicity distribution.