Muon <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>g</mml:mi><mml:mo>−</mml:mo><mml:mn>2</mml:mn></mml:math> at a multi-TeV muon collider
Wen Yin, Masahiro Yamaguchi
Abstract
The long-standing discrepancy of the muon anomalous magnetic moment ($g\ensuremath{-}2$) 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 $\mathcal{O}(10)\text{ }\text{ }\mathrm{TeV}$ with $\mathcal{O}(10)\text{ }\text{ }{\mathrm{ab}}^{\ensuremath{-}1}$. Even if there is no new particle in this energy range, one can measure the $g\ensuremath{-}2$ 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 $20[50]\ifmmode\times\else\texttimes\fi{}(\frac{{L}_{i}}{40\text{ }\text{ }{\mathrm{ab}}^{\ensuremath{-}1}}{)}^{\ensuremath{-}1/2}\text{ }\text{ }\mathrm{TeV}$ muon collider at the 2 [5] $\ensuremath{\sigma}$ level with ${L}_{i}$ being the integrated luminosity if the efficiency of the detector built in the future is almost perfect.