Journal article

Publication year: 2022

Journal: Physical Review D

Volume number: 106

Issue number: 9

ISSN: 2470-0010

eISSN: 2470-0029

Open access status: Hybrid

DOI Link: https://doi.org/10.1103/PhysRevD.106.094018

Publisher: American Physical Society

Abstract: 
A common feature of recent functional renormalization group investigations of effective low-energy QCD is the appearance of a backbending behavior of the chiral phase transition line at low temperatures together with a negative entropy density in the symmetric regime. The regulator scheme dependence of this phenomenon and the necessary modifications at finite densities are analyzed within a two-flavor quark-meson model. The flows at finite densities for three different regulators of three-or four-dimensional momenta are confronted with each other. It is found that the backbending behavior and the negative entropy density can be traced back to the explicit momentum dependence of the regulator shape function. While it persists for the often-used three-dimensional flat regulator, it vanishes for Callan-Symanzik type regulators. This points to truncation artifacts in the lowest order of the derivative expansion. A careful theoretical as well as numerical exploration is given.

Harvard Citation style: Otto, K., Busch, C. and Schaefer, B. (2022) Regulator scheme dependence of the chiral phase transition at high densities, Physical Review D, 106(9), Article 094018. https://doi.org/10.1103/PhysRevD.106.094018

APA Citation style: Otto, K., Busch, C., & Schaefer, B. (2022). Regulator scheme dependence of the chiral phase transition at high densities. Physical Review D. 106(9), Article 094018. https://doi.org/10.1103/PhysRevD.106.094018