Kazuki Kojima

18 July 2023
Lepton Photon 2023

Abstract: 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 $B \rightarrow D^{*}\ell^{-}\bar{\nu}_{\ell}$ and $B \rightarrow \pi\ell^{-}\bar{\nu}_{\ell}$ , $X_{c}\ell^{-}\bar{\nu}_{\ell}$ or $X_{u}\ell^{-}\bar{\nu}_{\ell}$ inclusive or 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.

Keyword(s): Semileptonic ; Semileptonic B decays ; Vcb ; Vub ; AFB ; R(D*) ; LFV ; LFUV ; FEI ; LP ; LP2023 ; Lepton Photon ; Lepton Photon 2023
Note: 15 minutes (12 minutes presentation + 3 minutes Q&A) https://www.leptonphoton2023.org/