Amending the Vafa-Witten Theorem    [PDF]

Chuan Li, Qing Wang
The strong version of the Vafa-Witten theorem is shown 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 \theta-angle. The existence of a charged \rho-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.
View original: http://arxiv.org/abs/1301.7009