Search for the QCD critical point by NA61/SHINE at the CERN SPS

TL;DR

This paper reviews the NA61/SHINE experiment's systematic search for the QCD critical point through fluctuation and correlation measurements across various collision energies and system sizes at CERN SPS.

Contribution

It presents a comprehensive analysis of fluctuation observables in different collision systems and energies, advancing the experimental search for the QCD critical point.

Findings

Evidence of non-monotonic fluctuation behavior under investigation

Systematic data across multiple collision systems and energies

Methodology for analyzing factorial moments of multiplicity distributions

Abstract

The existence and location of the QCD critical point is an object of both experimental and theoretical studies. The comprehensive data collected by the 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 scaling behavior of factorial moments of multiplicity distributions. This contribution reviews ongoing NA61/SHINE studies to search for the critical point of the strongly interacting matter.