$B \rightarrow \pi \ell \nu$ with M\"{o}bius Domain Wall Fermions

TL;DR

This paper reports on a lattice QCD calculation of the $B ightarrow \pi \ell u$ decay form factors using M"{o}bius domain wall fermions, aiming to improve the determination of the CKM element $|V_{ub}|$.

Contribution

The study employs M"{o}bius domain wall fermions for both light and heavy quarks on multiple lattice spacings, providing preliminary form factor results relevant for CKM matrix analysis.

Findings

Form factors depend on momentum transfer, lattice spacing, and heavy quark mass.

Calculations include pion masses down to 300 MeV and heavy quark masses up to 2.44 times charm.

Preliminary results show the feasibility of this approach for precise CKM matrix element extraction.

Abstract

We report on the status of our calculation of the exclusive semileptonic decay, $B\rightarrow \pi \ell \nu$; a key process in the determination of the CKM matrix element $|V_{ub}|$. The M\"{o}bius domain wall action is used for both light and heavy quarks on gauge ensembles that include the effects of $2+1$ flavours of quarks in the sea at three values of the lattice spacing: $a\approx 0.08~\mathrm{fm}$, $a\approx0.055~\mathrm{fm}$, and $a\approx0.044~\mathrm{fm}$. Pion masses go down to $300~\mathrm{MeV}$ while heavy quarks masses are as large as $2.44m_c$. We present preliminary results of form factors from this process, showing dependence on momentum transfer, lattice spacing, and the heavy quark mass.