Amending the Vafa-Witten Theorem
arXiv:1301.7009 · doi:10.1016/j.physletb.2013.02.050
Abstract
The strong version of the Vafa-Witten theorem is shown may not to hold because the zero condensate from a direct computation of the order parameter is found to be a result on the symmetric vacuum. The validity of the Vafa-Witten theorem relies then on its weak version, that the Goldstone boson is absent in vector-like gauge theories with vanishing θ-angle. The existence of a charged ρ-meson condensate, which violates electromagnetic gauge symmetry, is consistent with this weak version of the Vafa-Witten theorem when applied to strong magnetic fields in QCD.
6 pages