The \(\tau\) Magnetic Dipole Moment at Future Lepton Colliders

  • Arvind Rajaraman University of California, Irvine
  • Jessica N Howard University of California, Irvine
  • Rebecca Riley University of California, Irvine
  • Tim M. P. Tait University of California, Irvine
Keywords: Lepton Collider, Magnetic Moment


The magnetic moment of the $\tau$ lepton is an interesting quantity that is potentially sensitive to physics beyond the Standard Model. Electroweak gauge invariance implies that a heavy new physics contribution to it takes the form of an operator which involves the Higgs boson, implying that rare Higgs decays are able to probe the same physics as $a_\tau$. We examine the prospects for rare Higgs decays at future high energy lepton (electron or muon) colliders, and find that such a project collecting a few ab$^{-1}$ would be able to advance our understanding of this physics by roughly a factor of 10 compared to the expected reach of the high luminosity LHC.