Has the QCD critical point been observed at RHIC?

TL;DR

The paper critically examines recent claims of observing the QCD critical point at RHIC, arguing that the interpretation of experimental data is flawed due to incorrect scaling analysis, thus questioning the claimed discovery.

Contribution

The authors challenge previous claims by identifying errors in the scaling analysis, emphasizing the need for correct interpretation of critical phenomena in QCD phase diagram studies.

Findings

Previous claims of critical point observation are based on erroneous scaling relations.

Correct analysis does not support the identification of the QCD critical point at RHIC.

The universality class and critical exponents cannot be reliably extracted from the data as previously claimed.

Abstract

The experimental search for the location of the QCD critical point in the phase diagram is of primary importance. In a recent publication it is claimed that measurements at RHIC lead not only to the location of the critical point ($\mu_{cep}=95$ MeV, $T_{cep}=165$ MeV) but also to the verification of its universality class ($3d$ Ising system) by extracting the values of the critical exponents ($\gamma=1.2$, $\nu=0.66$). We argue that this claim is based on an erroneous treatment of scaling relations near the critical point. As a result, the correct interpretation of the measurements cannot be linked to the QCD critical point.