Muon collider signatures for a Z′ with a maximal μ − τ coupling in U(1)Lμ−Lτ

Abstract

The gauged U(1)Lμ−Lτ model is a candidate model for explaining the muon g-2 anomaly because the Z′ in the model has a natural normal coupling to muon. Due to other experimental data constraints the viable mass range for the usual Z′ is constrained to be lower than a few hundred MeV. It has been shown that if the Z′ has a maximal off-diagonal mixing, (μ¯γμτ+τ¯γμμ)Zμ′, a large mass for Z′ is possible. This class of models has a very interesting signature for detection, such as μ−μ+→τ−τ+ pair, μ−μ+→μ±μ±τ∓τ∓ at a muon collider. In this work we study in detail these processes. We find that in the parameter space solving the muon g-2 anomaly, t-channel τ−τ+ pair production can easily be distinguished at more than 5σ level from the s-channel production as that predicted in the standard model. The smoking gun signature of doubly same sign μ±μ±+τ∓τ∓ pairs production can have a 5σ sensitivity, at a muon collider of 3 TeV with O(fb−1) luminosity.