PU High Energy Theory Seminar
Symmetry Lost and Found
This talk will be held in-person in Jadwin Hall, PCTS Room 407 and on Zoom:
Zoom link: https://princeton.zoom.us/j/97248927011?pwd=SWFiNWFwZWE5SUR4OUxvV0ZacVdWQT09
Abstract: In massless QED, we find that the classical U(1) axial symmetry is not completely broken by the Adler-Bell-Jackiw anomaly. Rather, it is resurrected as a generalized global symmetry labeled by the rational numbers. Intuitively, this new global symmetry in QED is a composition of the naive axial rotation and a fractional quantum Hall state. The conserved symmetry operators do not obey a group multiplication law, but a non-invertible fusion algebra. We further generalize our construction to QCD, and show that the neutral pion decay can be derived from a matching condition of the non-invertible global symmetry. Finally, we find a non-invertible Gauss law in axion-Maxwell theory.