26-30 July 2021
Europe/Berlin timezone

Towards first $V_{ub}$ and $V_{cb}$ measurements at the Belle II experiment

27 Jul 2021, 09:45


Parallel session talk Flavour Physics and CP Violation T08: Flavour Physics and CP Violation


Mario Merola (INFN and Univ. Napoli)


Precision determinations of $V_{ub}$ and $V_{cb}$ play a central role in precision tests of the CKM sector of the Standard Model and complement direct measurements of CP violation of B meson decays. In this talk, we present first studies towards measurements of $|V_{ub}|$ and $V_{cb}$, with semileptonic decays using collision events recorded at the $\Upsilon(4S)$ resonance by the Belle II experiment. We report the status of measuring branching fractions and kinematic properties of inclusive and exclusive $b \to u \ell \bar \nu_\ell$ and $b \to c \ell \bar \nu_\ell$ decays using untagged and tagged approaches in the full available Belle II data set. In addition, we present a Belle II measurement of the $q^2$ moments of $B \rightarrow X_{c} \ell \nu$ decay. The $q^2$ moments of the $b \rightarrow c \ell \nu$ transition are particularly powerful for constraining the Heavy Quark Expansion as they can be expressed in terms of a reduced set of matrix elements due to reparametrization invariance.

Email libby@iitm.ac.in
Collaboration / Activity Belle II
First author Jim Libby

Presentation Materials