Theta terms and asymptotic behavior of gauge potentials in (3+1) dimensions
Abstract
We describe paths in the configuration space of (3+1) dimensional QED whose relative quantum phase (or relative phase in the functional integral) depends on the value of the theta angle. The final configurations on the two paths are related by a gauge transformation but differ in magnetic helicity or ChernSimons number. Such configurations must exhibit gauge potentials that fall off no faster than 1/r in some region of finite solid angle, although they need not have net magnetic charge (i.e., are not magnetic monopoles). The relative phase is proportional to theta times the difference in ChernSimons number. We briefly discuss some possible implications for QCD and the strong CP problem.
 Publication:

arXiv eprints
 Pub Date:
 July 2011
 arXiv:
 arXiv:1107.0756
 Bibcode:
 2011arXiv1107.0756H
 Keywords:

 High Energy Physics  Theory
 EPrint:
 v2 contains Note Added after Conclusions