Dynamical Chiral Symmetry Breaking and Superconductivity in the Supersymmetric Nambu$-$Jona-Lasinio Model at finite Temperature and Density

Abstract

We investigate the dynamical chiral symmetry breaking (DCSB) and superconductivity in a supersymmetric model at finite temperature and density. We employ the ${\cal N}=1$ four-dimensional generalized supersymmetric Nambu$-$Jona-Lasinio model (${\cal N}=1$ generalized ${\rm SNJL}_{4}$) with a chemical potential as the model Lagrangian, and select the gauge freedom as U(1). In order to realize the DCSB and BCS-type superconductivity in this model, we introduce a SUSY soft mass term. Under the finite-temperature Matsubara formalism, the effective potential and the gap equations are derived in the flamework of the large-N expansion. The finite-density effect in the DCSB is shown by the critical coupling. The roles of both the boson and fermion sectors in the superconductivity are examined by the quasiparticle excitation spectra and the gap equations.