Anomaly-free ALP from non-Abelian flavor symmetry

Abstract

Motivated by the Xenon1T excess in electron-recoil measurements, we investigate the prospects of probing axion-like particles (ALP) in lepton flavor violation experiments. In particular, we identify such ALP as a pseudo-Goldstone from the spontaneous breaking of the flavor symmetries that explain the mixing structure of the Standard Model leptons. We present the case of the flavor symmetries being a non-Abelian U(2) and the ALP originating from its U(1) subgroup, which is anomaly-free with the Standard Model group. We build two explicit realistic examples that reproduce leptonic masses and mixings and show that the ALP which is consistent with Xenon1T anomaly could be probed by the proposed LFV experiments.

Comments: 18 pages, 1 figure