Light vectors coupled to anomalous currents with harmless Wess-Zumino terms

Abstract

We reconsider the case of light vectors coupled to anomalous fermionic currents, focussing on the interplay between UV and IR dynamics. Taking as a general framework the gauging of the Standard Model accidental symmetries, we show that it is possible to devise an anomaly-free UV completion with mostly-chiral heavy fermions such that anomalous Wess-Zumino terms are suppressed in the IR, thus relaxing would-be strong bounds from the longitudinal emission of light vectors coupled to non-conserved currents. We classify such scenarios and show that they will be extensively probed at the high-luminosity phase of the LHC via the measurement of the $h\to Z\gamma$ rate and the direct search for non-decoupling charged leptons.

Comments: 23 pages, 1 figure. Minor corrections and references added. Matches published version