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  • Letter
  • Open Access

Locating the QCD critical point through contours of constant entropy density

Hitansh Shah1, Mauricio Hippert2,3, Jorge Noronha4, Claudia Ratti1, and Volodymyr Vovchenko1

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Phys. Rev. C 113, L012201 – Published 12 January, 2026

DOI: https://doi.org/10.1103/cbwj-4jfl

Abstract

We propose a new method to investigate the existence and location of the conjectured high-temperature critical point of strongly interacting matter via contours of constant entropy density. By approximating these lines as a power series in the baryon chemical potential μB, one can extrapolate them from first-principle results at zero net-baryon density, and use them to locate the quantum chromodynamics (QCD) critical point, including the associated first-order and spinodal lines. As a proof of principle, we employ currently available continuum-extrapolated lattice data from the Wuppertal-Budapest collaboration to find a critical point at a temperature and a baryon chemical potential of Tc=114.3±6.9 MeV and μB,c=602.1±62.1 MeV, respectively, at expansion order O(μB2). We advocate for a more precise determination of the required expansion coefficients via lattice QCD simulations as a means of pinpointing the location of the critical endpoint in the phase diagram of strongly interacting matter.

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Phys. Rev. C 113, L012201– Published 12 January, 2026
  • Received 14 November 2024
  • Revised 27 October 2025
  • Accepted 25 November 2025
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