Speaker
Description
Lepton flavor violation is one of the cleanest probes of physics beyond the standard model. In this work, we explore the sensitivity of the process $e^+e^-\to\tau\mu$ to new physics above the TeV scale at the proposed circular electron-positron colliders FCC-ee and CEPC. We compute the $e^+e^-\to\tau\mu$ cross-section in the Standard Model Effective Field Theory and assess the relevant backgrounds. We compare our sensitivity projections to existing and expected constraints from tau decays and $Z$ decays and find that the future electron-positron colliders provide competitive probes of new physics. We highlight the complementarity of searches for resonant $e^+e^-\to Z \to \tau\mu$ production on the $Z$ pole and searches for non resonant $e^+e^-\to\tau\mu$ at higher center-of-mass energies.
Name of collaboration or list of co-authors
Wolfgang Altmannshofer, Pankaj Munbodh and Talise Oh.
