https://doi.org/10.1140/epja/s10050-025-01718-y
Regular Article - Theoretical Physics
Vector interaction bounds in NJL-like models from LQCD estimated curvature of the chiral crossover line
1
School of Physical Sciences, National Institute of Science Education and Research, An OCC of Homi Bhabha National Institute, 752050, Jatni, India
2
Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
3
Center for Astrophysics and Cosmology, University of Nova Gorica, Vipavska 13, 5000, Nova Gorica, Slovenia
Received:
6
May
2025
Accepted:
10
October
2025
Published online:
25
October
2025
We obtain improved bounds on both the flavor-independent and -dependent vector interactions in a 
-flavor Nambu-Jona-Lasinio (NJL) model using the latest precise LQCD results of the curvature coefficients of the chiral crossover line. We find that these lattice estimated curvature coefficients allow for both attractive and repulsive types of interactions in both the cases. With this constrained ranges of vector interactions, we further predict the behavior of the second 
and fourth 
order curvature coefficients as a function of the strangeness chemical potential 
. We observe that the flavor mixing effects, arising from the flavor-independent vector interaction as well as from the ’t Hooft interaction, play an important role in 
. We propose that the mixing effects due to the vector interaction can be separated from those arising from the ’t Hooft interaction by analyzing the behavior of as a function of 
. Finally, we locate the critical endpoint in the 
plane using the model-estimated ranges of vector interactions and find the model’s predictions to be consistent with the latest LQCD bounds.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025
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.
