$B \to D^*\ell\nu$ decay in lattice QCD with domain-wall heavy quarks

by Takashi Kaneko

Tuesday 5 Mar 2024, 16:00 → 18:00 Europe/Zurich

4/2-037 - TH meeting room (CERN)

The $B \to D^*\ell\nu$ exclusive semileptonic decay provides the determination of the Cabibbo-Kobayashi-Maskawa matrix element |V_cb| as well as probe of new physics beyond the Standard Model (SM). The tension with |V_cb| from the inclusive decay,
however, suggests that theoretical and/or experimental uncertainties have not yet been fully understood. In this talk, we present our calculation of the $B \to D^*$ form factors, which are the source of the largest theoretical uncertainty, in lattice QCD with domain-wall heavy quarks. In contrast to the previous studies, the kinematical distribution of the decay shows good agreement with experiments. We report our estimate of $|V_{cb}|$ and $R(D^*) = \Gamma(B \to D^*\tau\nu)/\Gamma(B \to D^*{e,\mu}\nu)$, which shows one of the recent "B anomalies" between the SM and experiments.

lat_coffee_kaneko.pdf