Time : 2022/03/31 (Thu.) 12:30
Title: U(1)_{L_\mu - L_\tau} for muon g-2, small vs large Z' mass

Abstract:
Muon g-2 anomaly at 4.2 sigma level excess compared with SM
prediction is a long standing problem in particle physics. Many model
have been proposed to solve the problem. The U(1)_{L_\mu - L_\tau} model
is a commonly discussed model due to its simplicity, the smallest
extension of the SM to have an additional gauge boson Z'. Exchange Z' in
this model can naturally provide the needed excess to solve the muon g-2
anomaly. When take into account constraint from the trident neutrino
process \nu_\mu N \to \nu_\mu N \mu \bar mu$,  the Z' mass of the
minimal model is constrained to very small, less than a few hundred
MeV. This has been taken as a firm fact by many. In this talk, I will
show that this needs not to be the case. With modifications, the trident
neutrino constraint can be invaded and the Z' mass can be large. The
model has distinct signatures which can be verified by collider
experiments.