Semileptonic and Leptonic Decays at Belle II

TL;DR

This paper reviews recent Belle II studies on semileptonic and leptonic B decays, testing lepton flavor universality and refining CKM matrix element measurements using extensive collision data.

Contribution

It presents new analyses of Belle II data that improve the understanding of B decays and contribute to precision tests of the Standard Model.

Findings

Tests of lepton flavor universality with current data

Improved measurements of |V_{ub}| and |V_{cb}|

Analysis of 711 fb^{-1} Belle and 365 fb^{-1} Belle II data samples

Abstract

This proceeding summarises recent studies on semileptonic and leptonic $B$ decays, which provide stringent tests of lepton flavour universality as well as key experimental inputs to ultimately increase the precision of inclusive $|V_{ub}|$ and $|V_{cb}|$ determinations. The presented analyses investigate electron-positron collision data recorded by the Belle and Belle II detectors at the $\Upsilon(4S)$ resonance, comprising the complete Belle data set of 711 fb$^{-1}$ and 365 fb$^{-1}$ of Belle II data samples collected between 2019 - 2022.