$B_s \to D^{(*)}_s$ form factors from lattice QCD with ${ N_f}=2$ Wilson-clover quarks

TL;DR

This paper presents a lattice QCD calculation of $B_s o D_s^{(*)}$ transition form factors, providing essential theoretical inputs for testing lepton-flavour universality and exploring potential New Physics effects.

Contribution

It introduces a method to extract $b o c$ transition form factors from lattice QCD, with numerical results for $ ext{G}$ and $h_{A_1}$ form factors.

Findings

Numerical results for $ ext{G}$ and $h_{A_1}$ form factors obtained.

Method demonstrated for extracting $b o c$ form factors from lattice QCD.

Highlights the relevance of $B_s$ decay channels in New Physics searches.

Abstract

We report on a two-flavour lattice QCD determination of the $B_s\to D_s$ and $B_s\to D_s^*$ transitions, which in the heavy quark limit can be parameterised by the form factors $\mathcal{G}$, and $h_{\text A_1}$, $h_{\text A_2}$ and $h_{\text A_3}$. In the search of New Physics through tests of lepton-flavour universality, $B_s$ decay channels are complementary to $B$ decays and widely studied at $B$ factories and LHCb. The purpose of our study is to explore a suitable method to extract form factors associated with $b\to c$ currents from lattice QCD. In particular, we present numerical results for $\mathcal{G}$ and $h_{\text A_1}$.