Influence of QED Corrections on the Orientation of Chiral Symmetry Breaking in the NJL model

Abstract

We study QED corrections to chiral symmetry breaking in the Nambu--Jona-Lasinio (NJL) model with two flavors of quarks. In this model, the isospin symmetry is broken by the differences between the current quark masses and the electromagnetic charges of the up and down quarks. To leading order in the 1/N expansion, we calculate the effective potential of the model with one-loop QED corrections at finite temperature. Evaluating the effective potential, we study the influence of the isospin symmetry breaking on the orientation of chiral symmetry breaking. The current quark mass plays an essential role in maintaining the orientation of the chiral symmetry breaking. If the average of the up and down quark masses is small enough, we find a phase in which the pion field has non-vanishing expectation value and dynamical CP violation takes place.

arXiv comment22 pages, 13 figures; added discussion about pion mass difference

References in corpus (8)

• QCD Phenomenology based on a Chiral Effective Lagrangian
• Four-fermion Interaction Model in a Constant Magnetic Field at Finite Temperature and Chemical Potential
• Phase Structure of Four-Fermion Theories at Finite Temperature and Chemical Potential in Arbitrary Dimensions
• Disoriented Chiral Condensate: Theory and Experiment
• Dynamical symmetry breaking in the external gravitational and constant magnetic fields
• Dynamical symmetry breaking in the Nambu-Jona-Lasino model with external gravitational and constant electric fields
• Dynamical CP Violation in Composite Higgs Models - a Review -
• Dynamical CP Violation in Composite Higgs Models

Cited by in corpus (15)

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• Spontaneous CP-violation in the strong interaction at theta = pi
• High density quark matter in the NJL model with dimensional vs. cut-off regularization
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• $\pi$ and $\sigma$ mesons at finite temperature and density in the NJL model with dimensional regularization
• Theta vacuum and entanglement interaction in the three-flavor Polyakov-loop extended Nambu-Jona-Lasinio model
• CP violation and chiral symmetry breaking in hot and dense quark matter in presence of magnetic field
• Isospin symmetry breaking and baryon-isospin correlations from Polyakov$-$Nambu$-$Jona-Lasinio model
• Anomalous $U(1{)}_A$ couplings and the Columbia plot
• Violations of parity and charge conjugation in the theta vacuum with imaginary chemical potential
• Spontaneous parity and charge-conjugation violations at real isospin and imaginary baryon chemical potentials
• Strong CP violation and chiral symmetry breaking in hot and dense quark matter
• The role of $U(1{)}_A$ symmetry breaking in the QCD corrections to the pion mass difference
• Practical approach to the sign problem at finite theta-vacuum angle
• A practical solution to the sign problem at finite theta-vacuum angle