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arXiv · 1912.09946

Semileptonic $B\to\pi\ell\nu$, $B\to D\ell\nu$, $B_s\to K\ell\nu$, and $B_s\to D_s\ell\nu$ decays

Jonathan Flynn·Ryan Hill·Andreas Jüttner·Amarjit Soni·Justus Tobias Tsang·Oliver Witzel
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Abstract

We present updates for our nonperturbative lattice QCD calculations to determine semileptonic form factors for exclusive $B\to \pi\ell\nu$, $B\to D \ell\nu$, $B_s\to K\ell \nu$, and $B_s\to D_s\ell\nu$ decays. Our calculation is based on RBC-UKQCD's set of $2+1$-dynamical-flavor gauge field ensembles. In the valence sector we use domain wall fermions for up/down, strange and charm quarks, whereas bottom quarks are simulated with the relativistic heavy quark action. The continuum limit is based on three lattice spacings. Using kinematical $z$ expansions we aim to obtain form factors over the full $q^2$ range. These form factors are the basis for predicting ratios addressing lepton flavor universality or, when combined with experimental results, to obtain CKM matrix elements $|V_{ub}|$ and $|V_{cb}|$.

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Jonathan Flynn, Ryan Hill, Andreas Jüttner, Amarjit Soni, Justus Tobias Tsang, Oliver Witzel. 2019-12-20. Semileptonic $B\to\pi\ell\nu$, $B\to D\ell\nu$, $B_s\to K\ell\nu$, and $B_s\to D_s\ell\nu$ decays. https://arxiv.org/abs/1912.09946

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