Study of $B\to\pi\ell\nu_{\ell}$ and $B^{+}\to\eta^{(\prime)}\ell^{+}\nu_{\ell}$ decays and determination of $|V_{ub}|$

TL;DR

This paper combines experimental data and lattice calculations using Padé approximants to accurately determine the CKM matrix element |V_{ub}| from B meson decays, also exploring related semileptonic decay channels.

Contribution

It introduces a novel analysis method employing Padé approximants to reassess B decay data and extract |V_{ub}| with improved precision, including decay channels involving eta and eta' mesons.

Findings

Determined |V_{ub}| = 3.53(8)_{stat}(6)_{syst} x 10^{-3}

Provided detailed analysis of B→πℓν decays using combined data and lattice form factors

Discussed η-η' mixing in semileptonic B decays.

Abstract

We reassess the $B\to\pi\ell\nu_{\ell}$ differential branching ratio distribution experimental data released by the BaBar and Belle Collaborations supplemented with all lattice calculations of the $B\to\pi$ form factor shape available up to date obtained by the HPQCD, FNAL/MILC and RBC/UKQCD Collaborations. Our study is based on the method of Pad\'{e} approximants, and includes a detailed scrutiny of each individual data set that allow us to obtain $|V_{ub}|=3.53(8)_{\rm{stat}}(6)_{\rm{syst}}\times10^{-3}$. The semileptonic $B^{+}\to\eta^{(\prime)}\ell^{+}\nu_{\ell}$ decays are also addressed and the $\eta$-$\eta^{\prime}$ mixing discussed.