# The 39th International Symposium on Lattice Field Theory (Lattice 2022)

Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
Europe/Berlin timezone

## A lattice QCD study of the B \to \pi\pi \ell \nu transition

Aug 8, 2022, 2:40 PM
20m
CP1-HSZ/1st-1.002 - HS6 (CP1-HSZ)

### CP1-HSZ/1st-1.002 - HS6

#### CP1-HSZ

50
Oral Presentation Weak Decays and Matrix Elements

### Speaker

Luka Leskovec (Jozef Stefan Institute)

### Description

$V_{ub}$ is the smallest and least known of all CKM matrix elements; the community determines its current value primarily through the exclusive process $B\to\pi\ell\nu$. This talk will present our progress toward a lattice QCD determination of the $V_{ub}$ matrix element from a novel transition - $B \to \pi\pi\ell\nu$ process, where the $\pi\pi$ rescattering features the $\rho(770)$ resonance as an enhancement. We perform our calculation on $N_f=2+1$ clover fermions on a lattice of $L=3.6$ fm and a pion mass of $320$ MeV. After a brief overview of the theoretical framework, we will discuss some preliminary results.

### Primary author

Luka Leskovec (Jozef Stefan Institute)

### Co-authors

Stefan Meinel (University of Arizona) Dr Marcus Petschlies (Helmholtz-Instituts für Strahlen- und Kernphysik) Constantia Alexandrou Andrew Pochinsky (MIT) Gumaro Rendon (Brookhaven National Laboratory) John Negele (MIT) Srijit Paul (Johannes Gutenberg University Mainz)