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New 4D lattice QCD equation of state: Extended density coverage from a generalized T′ expansion

Ahmed Abuali1, Szabolcs Borsányi2, Zoltán Fodor3,4,2,5,6, Johannes Jahan1,*, Micheal Kahangirwe1, Paolo Parotto7, Attila Pásztor5, Claudia Ratti1, Hitansh Shah1 et al.

Seth A. Trabulsi8

  • *Contact author: jahan.johannes@gmail.com
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Phys. Rev. D 112, 054502 – Published 9 September, 2025

DOI: https://doi.org/10.1103/2dmh-26yh

Abstract

We present a new equation of state for QCD in which the temperature T and the three chemical potentials for baryon number μB, electric charge μQ, and strangeness μS can be varied independently. This result is based on a generalization of the T′ expansion scheme, thanks to which the diagonal μB extrapolation was pushed up to a baryo-chemical potential μB/T∼3.5 for the first time. This considerably extended the coverage of the Taylor expansion, limited to μB/T<2.5–3. As a consequence, we are able to offer a substantially larger coverage of the four-dimensional QCD phase diagram as well, compared to previously available Taylor expansion results. Our findings are based on new continuum estimated lattice data on the full set of second- and fourth-order fluctuations.

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Phys. Rev. D 112, 054502– Published 9 September, 2025
  • Received 10 May 2025
  • Accepted 6 August 2025
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