# EPS-HEP2019

10-17 July 2019
Ghent
Europe/Brussels timezone

## New results on the magnitudes of the CKM elements |V_{cb}| and |V_{ub}| from Belle

12 Jul 2019, 09:35
20m
Campus Ledeganck - Aud. 5 (Ghent)

### Campus Ledeganck - Aud. 5

#### Ghent

Parallel talk Flavour Physics and CP Violation

### Speaker

Florian Urs Bernlochner (KIT - Karlsruhe Institute of Technology (DE))

### Description

The magnitudes of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, in combination with the angles of the Unitarity Triangle, are crucial for testing the standard model. We report a new determination of $|V_{cb}|$ based on $B \to D^* l^+ \nu$ decays in untagged events. Different parameterizations of the semileptonic form factor are used in the extraction of this CKM matrix element. Finally, we also cover the new Belle search for the purely leptonic decay $B \to \mu^+ \nu$, which will allow to determine $|V_{ub}|$. The analyses are based on the full data set recorded by the Belle detector at the KEKB $e^+ e^-$ collider containing 772 million $B\bar{B}$ pairs.