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Effect of the charm quark on the QCD chiral phase diagram

Fei Gao1, Yuepeng Guan2, and Shinya Matsuzaki2

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Phys. Rev. D 114, 014016 – Published 6 July, 2026

DOI: https://doi.org/10.1103/8r63-rztg

Abstract

We study the influence of charm-quark dynamics on the chiral phase structure of QCD using the recently developed miniDSE scheme for the Dyson-Schwinger equations. By comparing the quark and gluon propagators in the 2+1- and 2+1+1-flavor setups within the same truncation scheme, we qualify the impact of the charm-quark loop on the QCD phase diagram. Our results show that the charm quark has only a mild effect on the crossover boundary, which remains almost unchanged within the present setup. The most visible effect is a small shift of the critical endpoint (CEP) toward lower baryon chemical potential, by approximately 3%. The present result provides a controlled estimate of the charm-loop effect within the same miniDSE truncation. It indicates that heavy-flavor contributions may become relevant when aiming at precision studies of the CEP location.

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Phys. Rev. D 114, 014016– Published 6 July, 2026
  • Received 13 March 2026
  • Accepted 15 June 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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