Phase structure of quantum electrodynamics in the framework of the SchwingerDyson equation
Abstract
Based on a solution of the coupled SchwingerDyson equation, we study the effect of vacuum polarization and the number of flavors N_{f} on the dynamics of spontaneous chiral symmetry breaking in quantum electrodynamics. In the Landau and Feynman gauges, it is shown that there exists a transition between a weak coupling phase and a strong coupling phase where chiral symmetry is spontaneously broken for 0<=N_{f}<∞, although, in the limit N_{f}=∞, the spontaneous breaking of the chiral symmetry does not occur in any gauge. The spontaneous chiral transition is always continuous, but the order of the transition changes depending on N_{f}: (1) for N_{f}=0, the chiral transition is of essentially singularity type, (2) for large (finite) N_{f}, however, the chiral transition exhibits powerlaw dominated behavior, even for N_{f}=1, which is gaugeparameter independent. In connection with this result, the continuum limit of QED is discussed.
 Publication:

Physics Letters B
 Pub Date:
 March 1989
 DOI:
 10.1016/03702693(89)900506
 Bibcode:
 1989PhLB..220..270K