Chiral-symmetry restoration in the Nambu--Jona-Lasinio model with a constant electromagnetic field
The proper-time Schwinger formalism is implemented in a derivation of the gap equation and total energy of a system of interacting fermions described by the Nambu--Jona-Lasinio model that is minimally coupled to a constant electromagnetic field. Inclusion of a Lagrange multiplier term to vary the scalar density enables the calculation of energy curves as a function of the scalar density that plays the role of an order parameter. A consistent gauge- and Lorentz-invariant regularization of the divergent quantities that occur in this theory is implemented in calculating the total energy and gap relation. Specializing to constant electric fields, we find that a chiral-symmetry-restoration phase transition can occur at a critical value of the electric field. For our choice of parameters, /ital g/..lambda../sup 2//2..pi../sup 2/=1.12 and ..lambda..=1041 MeV, one finds the dynamically generated mass /ital m//sub /ital E/=0//sup */=208 MeV and critical field /ital eE//sub /ital c//=(270 MeV)/sup 2/. By contrast, aconstant magnetic field is found to inhibit the phase transition by stabilizingthe chirally broken vacuum state.
- Research Organization:
- Physics Department and Wits-CSIR Schonland Centre for Nuclear Sciences, University of the Witwatersrand, P.O. Wits, 2050, Johannesburg, South Africa(ZA)
- OSTI ID:
- 6391487
- Journal Information:
- Phys. Rev. D; (United States), Vol. 39:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHIRAL SYMMETRY
FERMIONS
SYMMETRY BREAKING
PARTICLE INTERACTIONS
DIRAC EQUATION
ELECTRIC FIELDS
ELECTROMAGNETIC FIELDS
LORENTZ INVARIANCE
MAGNETIC FIELDS
MASS
MEAN-FIELD THEORY
PHASE TRANSFORMATIONS
PROPAGATOR
RENORMALIZATION
VACUUM STATES
DIFFERENTIAL EQUATIONS
EQUATIONS
INTERACTIONS
INVARIANCE PRINCIPLES
PARTIAL DIFFERENTIAL EQUATIONS
SYMMETRY
WAVE EQUATIONS
645300* - High Energy Physics- Particle Invariance Principles & Symmetries
645400 - High Energy Physics- Field Theory