Speaker
Description
Semileptonic $B$-meson decays allow for determining the magnitudes of the CKM matrix parameters $|V_{cb}|$ and $|V_{ub}|$, two fundamental parameters of the SM flavor sector and to probe the excess rate of semitauonic $B$ decays, which has been consistently above expectations in recent years. Belle II analyses use both exclusive decays such as $B \to D^*\ell \nu$ and $B \to \pi \ell \nu$, or inclusive $X_c \ell \nu$ or $X_u \ell \nu$ final states restricted in phase space. The low-background collision environment, along with the possibility of partially or fully reconstructing one of the two $B$ mesons in the event, offer precisions on $|V_{cb}|$ and $|V_{ub}|$ approaching that of world-best results and provides unique probes of lepton-flavor universality violation.
