https://doi.org/10.1140/epja/s10050-024-01469-2
Regular Article - Theoretical Physics
Describing the speed of sound peak of isospin-asymmetric cold strongly interacting matter using effective models
1
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Ext. S/N Ciudad Universitaria, 04510, CdMx, Mexico
2
Departamento de Física, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil
Received:
13
June
2024
Accepted:
8
December
2024
Published online:
24
December
2024
The non-monotonic behavior of the speed of sound for isospin imbalanced strongly interacting matter, found by recent lattice QCD simulations, can be reproduced within the Nambu–Jona-Lasinio model and Linear Sigma Model with quarks when the couplings become isospin chemical potential-dependent. The introduction of medium-dependent couplings can potentially affect the equivalence between the thermodynamic relations and their definitions from statistical mechanics. We describe the procedure to compensate for the introduction of medium-dependent couplings to preserve the correct thermodynamic identities. We find the isospin chemical potential dependence for the couplings from the isospin density LQCD data and, after finding the compensating function to correctly describe the pressure, we show that the description of the square of the speed of sound reported by LQCD is well reproduced when using the found medium-dependent couplings in both models.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
