https://doi.org/10.1140/epjs/s11734-025-02085-x
Regular Article
Quark mass dependence of a QCD critical point and structure of the Columbia plot
1
Institut für Theoretische Physik, Justus-Liebig-Universität Gießen, 35392, Giessen, Germany
2
Helmholtz Forschungsakademie Hessen für FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung, Campus Gießen, 35392, Giessen, Germany
a
This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
6
August
2025
Accepted:
27
November
2025
Published online:
5
December
2025
Abstract
We study the quark-mass dependence of the QCD critical point at varying bare up/down quark masses with fixed strange quark mass. We explore the corresponding second-order critical surface in the three-dimensional Columbia plot and study the extension of the associated crossover hyperplane at real and imaginary baryon chemical potential. To this end, we employ a by now well-tested combination of lattice Yang–Mills theory and a (truncated) version of Dyson–Schwinger equations at 
quark flavours. We find evidence for a positive curvature of the second-order surface at (large) real chemical potential and a crossover region for imaginary chemical potential. Our results support the notion of a tricritical point at finite chemical potential in the chiral limit.
© The Author(s) 2025
modified publication 2026
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
