Analytic structure of the quark propagator in a model with an infrared vanishing gluon propagator

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.53.446· OSTI ID:253526

Bender, A ^[1]; Alkofer, R ^[2]

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1. Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843 (United States)
2. Institut fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)

The Dyson-Schwinger equation for the quark self-energy is solved in the rainbow approximation using an infrared (IR) vanishing gluon propagator that introduces an IR mass scale {ital b}. There exists a {ital b}-dependent critical coupling indicating the spontaneous breakdown of chiral symmetry. If one chooses realistic QCD coupling constants the strength and the scale of spontaneous chiral symmetry breaking decouple from the IR scale for small {ital b} while for large {ital b} no dynamical chiral symmetry breaking occurs. At timelike momenta the quark propagator possesses a pole, at least for a large range of the parameter {ital b}. Therefore, it is suggestive that quarks are not confined in this model for all values of {ital b}. Furthermore, we argue that the quark propagator is analytic within the whole complex momentum plane except on the timelike axis. Hence the naive Wick rotation is allowed. {copyright} {ital 1995 The American Physical Society.}

• OSTI ID: 253526
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 1 Vol. 53; ISSN 0556-2821; ISSN PRVDAQ
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CHIRAL SYMMETRY
COUPLING
GLUONS
PROPAGATOR
QUANTUM CHROMODYNAMICS
QUARKS
SCHWINGER FUNCTIONAL EQUATIONS
SELF-ENERGY
SYMMETRY BREAKING