Muon g-2 at a multi-TeV muon collider

Abstract

The long-standing discrepancy of the muon anomalous magnetic moment (g-2) is a hint of new physics beyond the standard model of particle physics. In this paper, we show that heavy new physics contribution can be fully tested at a muon collider with a center-of-mass energy up to O(10) TeV with O(10) ab-1. Even if there is no new particle in this energy range, one can measure the g-2 operator directly via the channel to a Higgs boson and a monochromatic photon. In particular, the latter process, which is the most challenging case, can be tested in the 20[50]×(Li40 ab-1)-1/2 TeV muon collider at the 2 [5] σ level with Li being the integrated luminosity if the efficiency of the detector built in the future is almost perfect.