Studying explicit 
U(1)A
 symmetry breaking in a hot and magnetized two flavor nonlocal NJL model constrained using lattice results

Mahammad Sabir Ali; Chowdhury Aminul Islam; Rishi Sharma

doi:10.1103/physrevd.104.114026

Dynamical breaking to special or regular subgroups in the SO(N) Nambu–Jona-Lasinio model

Progress of Theoretical and Experimental Physics ◽

10.1093/ptep/ptaa001 ◽

2020 ◽

Vol 2020 (2) ◽

Author(s):

Taichiro Kugo ◽

Naoki Yamatsu

Keyword(s):

Symmetry Breaking ◽

Spinor Representation ◽

Njl Model ◽

Dynamical Breaking ◽

Irreducible Spinor

Abstract It was recently shown that in four-dimensional $SU(N)$ Nambu–Jona-Lasinio (NJL) type models, the $SU(N)$ symmetry breaking into its special subgroups is not special but much more common than that into the regular subgroups, where the fermions belong to complex representations of $SU(N)$. We perform the same analysis for the $SO(N)$ NJL model for various $N$ with fermions belonging to an irreducible spinor representation of $SO(N)$. We find that the symmetry breaking into special or regular subgroups has some correlation with the type of fermion representations; i.e. complex, real, pseudo-real representations.

Download Full-text

DYNAMICAL SYMMETRY BREAKING IN THE EXTERNAL GRAVITATIONAL AND CONSTANT MAGNETIC FIELDS

International Journal of Modern Physics A ◽

10.1142/s0217751x99000245 ◽

1999 ◽

Vol 14 (04) ◽

pp. 481-503 ◽

Cited By ~ 24

Author(s):

T. INAGAKI ◽

S. D. ODINTSOV ◽

YU. I. SHIL'NOV

Keyword(s):

Magnetic Field ◽

Gravitational Field ◽

Magnetic Fields ◽

Symmetry Breaking ◽

Effective Potential ◽

Constant Magnetic Field ◽

Dynamical Symmetry ◽

Green Functions ◽

Dynamical Symmetry Breaking ◽

Njl Model

We investigate the effects of the external gravitational and constant magnetic fields to the dynamical symmetry breaking. As simple models of the dynamical symmetry breaking we consider the Nambu–Jona-Lasinio (NJL) model and the supersymmetric Nambu–Jona-Lasinio (SUSY NJL) model nonminimally interacting with the external gravitational field and minimally interacting with constant magnetic field. The explicit expressions for the scalar and spinor Green functions are found to the first order in the space–time curvature and exactly for a constant magnetic field. We obtain the effective potential of the above models from the Green functions in the magnetic field in curved space–time. Calculating the effective potential numerically with the varying curvature and/or magnetic fields we show the effects of the external gravitational and magnetic fields to the phase structure of the theories. In particular, increase of the curvature in the spontaneously broken phase of the chiral symmetry due to the fixed magnetic field makes this phase to be less broken. At the same time the strong magnetic field quickly induces chiral symmetry breaking even in the presence of fixed gravitational field within the nonbroken phase.

Download Full-text

MESONS AND DIQUARKS IN A NJL MODEL AT FINITE TEMPERATURE AND CHEMICAL POTENTIAL

International Journal of Modern Physics A ◽

10.1142/s0217751x93000539 ◽

1993 ◽

Vol 08 (07) ◽

pp. 1295-1312 ◽

Cited By ~ 44

Author(s):

D. EBERT ◽

YU. L. KALINOVSKY ◽

L. MÜNCHOW ◽

M.K. VOLKOV

Keyword(s):

Symmetry Breaking ◽

Chiral Symmetry ◽

Finite Temperature ◽

Chemical Potential ◽

Chiral Symmetry Breaking ◽

Baryon Number ◽

Coupling Constants ◽

Number Density ◽

Njl Model

An extended NJL model with [Formula: see text] and (qq)-interactions is studied at finite temperature and baryon number density. We investigate the chiral symmetry breaking, its restoration and the behavior of meson and diquark masses, decay and coupling constants as functions of T and µ.

Download Full-text

Supersymmetric Nambu–Jona-Lasinio Model in an External Gravitational Field

Modern Physics Letters A ◽

10.1142/s021773239700234x ◽

1997 ◽

Vol 12 (30) ◽

pp. 2271-2277 ◽

Cited By ~ 11

Author(s):

I. L. Buchbinder ◽

T. Inagaki ◽

S. D. Odintsov

Keyword(s):

Gravitational Field ◽

Symmetry Breaking ◽

Chiral Symmetry ◽

Effective Potential ◽

Chiral Symmetry Breaking ◽

Leading Order ◽

Gravitational Fields ◽

External Gravitational Field ◽

Njl Model ◽

Curvature Approximation

We investigate the effect of an external gravitational fields to the chiral symmetry breaking in the supersymmetric (SUSY) Nambu–Jona-Lasinio (NJL) model coupled to gravity in a non-supersymmetric way. Evaluating the effective potential in the leading order of the 1/Nc-expansion and in the linear curvature approximation, it is possible to have the chiral symmetry breaking in the SUSY NJL model in an external gravitational fields. In the broken phase the dynamically generated mass is analytically and numerically calculated.

Download Full-text