Speaker
Description
The electric and magnetic dipole moments of the electron and muon provide stringent tests of the Standard Model and sensitive probes of new physics. In contrast, the corresponding dipole moments of the tau lepton, well motivated in scenarios with enhanced couplings to third-generation fermions, remain weakly constrained. In our work, we investigate the potential to probe the tau dipole moments at future lepton colliders, focusing on the $e^+e^-$ Future Circular Collider and a high-energy muon collider. We perform a broad analysis on the expected sensitivity on the tau dipole moments that can be reached at such facilities. In order to do so, we consider several different processes, including $\ell^+\ell^- \to \tau^+\tau^-$ ($\ell=e,\mu$), photon-photon collisions $\gamma\gamma \to \tau^+\tau^-$, radiative Higgs decays $H \to \tau^+\tau^-\gamma$, associated Higgs production $\mu^+\mu^- \to \tau^+\tau^- H$, and vector-boson scatterings $\mu^+\mu^- \to \mu^+\mu^-\tau^+\tau^-(H)$, $\mu^+\mu^- \to \bar{\nu}\nu\tau^+\tau^-(H)$, and $\mu^+\mu^- \to \mu\nu\tau\nu\,(H)$. In this talk I will discuss how these channels can be employed to extend the existing bounds by several orders of magnitude.