Work

Assessing the reconstruction of the critical line in the QCD phase diagram from imaginary to real chemical potential

Year: 2025

Type: article

Abstract: We test a technique adopted in the lattice simulations framework, to reconstruct the chiral-phase boundary at real chemical potential, μ , via extrapolation from imaginary μ . We use a low-energy effective model, the quark-meson model, both in the mean-field approximation and within the functional renormalization group, the latter in the local potential approximation. The model provides results both for real and imaginary values of μ ; thus a direct comparison can be performed between the prediction of the model for real values of μ and the ones obtained via extrapolation from the results at imaginary μ . We compute an effective convergence radius for the reconstruction technique, μ conv , and find μ conv ≈ 263 MeV . This value sustains the validity of the reconstruction technique also for finite and moderate values of the chemical potential. On the other hand, within our model, μ conv is smaller then the value of μ where we find the actual critical endpoint. Near this point of the phase diagram, we find a discrepancy between the actual phase boundary and the one obtained via extrapolation of ≈ 100 % . Therefore, our results show that the location of the critical endpoint obtained via reconstruction from imaginary μ might be considered with due caution.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/vl7y-j84r

Authors: Fabrizio Murgana, Marco Ruggieri

Institutions: University of Catania, Istituto Nazionale di Fisica Nucleare, Sezione di Catania

Language: English

Topic: High-Energy Particle Collisions Research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: European Commission, Ministero dell'Università e della Ricerca, NextGenerationEU

Awards: G6931409086, G972786147, G973128541