Photon pairing in massless quantum electrodynamics
Abstract
Instability of quantum electrodynamics with a massless electron due to photon pairing is studied. Through the box diagram, the photonphoton interaction turns out to be attractive and the twophoton bound state becomes tachyonic. The critical coupling for this phenomenon is zero. The influence of photon pairing on the chiral symmetry breaking is also discussed, which suggests that the critical coupling for the chiral symmetry breaking is also zero.
 Publication:

Physics Letters B
 Pub Date:
 December 1991
 DOI:
 10.1016/03702693(91)90308D
 Bibcode:
 1991PhLB..273..519I