$\overline{B}\rightarrow D^\ast\ell\overline{\nu}$ at non-zero recoil

TL;DR

This paper reports preliminary lattice QCD calculations of form factors for the $ar{B} o D^* ar{ u}$ decay at non-zero recoil, aiming to improve the determination of the CKM matrix element $|V_{cb}|$.

Contribution

The study provides new lattice QCD results for form factors at non-zero recoil using multiple ensembles and improved actions, advancing the precision of $|V_{cb}|$ determination.

Findings

Form factors computed for 15 ensembles with varying lattice spacings.

Results will refine the extraction of $|V_{cb}|$ when combined with experimental data.

Future plans include further analysis and phenomenological applications.

Abstract

We present preliminary results from our analysis of the form factors for the $\overline{B}\rightarrow D^\ast\ell\overline{\nu}$ decay at non-zero recoil. Our analysis includes 15 MILC asqtad ensembles with $N_f=2+1$ flavors of sea quarks and lattice spacings ranging from $a\approx 0.15$ fm down to $0.045$ fm. The valence light quarks employ the asqtad action, whereas the heavy quarks are treated using the Fermilab action. We conclude with a discussion of future plans and phenomenological implications. When combined with experimental measurements of the decay rate, our calculation will enable a determination of the CKM matrix element $|V_{cb}|$.