Eur. Phys. J. Plus (2020) 135: 43
https://doi.org/10.1140/epjp/s13360-019-00004-3

Regular Article

Thermodynamic geometry of Nambu–Jona Lasinio model

¹ Dipartimento di Fisica, Università di Catania, Via Santa Sofia 64, 95123, Catania, Italy
² INFN, Sezione di Catania, 95123, Catania, Italy
³ Dipartimento di Fisica, Università di Roma “La Sapienza”, Piazzale Aldo Moro 2, 00185, Rome, Italy
⁴ Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000, Prague 8, Czech Republic

^* e-mail: daniele.lanteri@ct.infn.it

Received: 24 July 2019
Accepted: 20 December 2019
Published online: 13 January 2020

Abstract

The formalism of Riemannian geometry is applied to study the phase transitions in Nambu–Jona Lasinio (NJL) model. Thermodynamic geometry reliably describes the phase diagram, both in the chiral limit and for finite quark masses. The different thermodynamic geometrical behavior of NJL model and of (2+1) Quantum Chromodynamics at high temperature and small baryon density gives some hints on the connection between chiral symmetry restoration/breaking and deconfinement/confinement regimes.