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Curvature of the pseudocritical line in the QCD phase diagram from mesonic lattice correlation functions

Antonio Smecca1,*, Gert Aarts1, Chris Allton1, Ryan Bignell2, Benjamin Jäger3, Seung-il Nam4, Seyong Kim5, Jon-Ivar Skullerud6,2, and Liang-Kai Wu7

  • *Contact author: antonio.smecca@swansea.ac.uk
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Phys. Rev. D 112, 114509 – Published 15 December, 2025

DOI: https://doi.org/10.1103/wjm8-4smh

Abstract

In the QCD phase diagram, the dependence of the pseudocritical temperature, Tpc, on the baryon chemical potential, μB, is of fundamental interest. The variation of Tpc with μB is normally captured by κ, the coefficient of the leading (quadratic) term of the polynomial expansion of Tpc with μB. In this work, we present the first calculation of κ using hadronic quantities. Simulating Nf=2+1 flavors of Wilson fermions on fastsum ensembles, we calculate the O(μB2) correction to mesonic correlation functions. By demanding degeneracy in the vector and axial-vector channels we obtain Tpc(μB) and hence κ. While lacking a continuum extrapolation and being away from the physical point, our results are consistent with previous works using thermodynamic observables (renormalized chiral condensate, strange quark number susceptibility) from lattice QCD simulations with staggered fermions.

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Phys. Rev. D 112, 114509– Published 15 December, 2025
  • Received 16 February 2025
  • Accepted 24 November 2025
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