$B \to D^* l \nu$ with staggered chiral perturbation theory

TL;DR

This paper presents a staggered chiral perturbation theory calculation crucial for accurately determining the $B o D^* l u$ form factor, which is essential for precise measurement of the CKM matrix element |V_{cb}| using lattice QCD data.

Contribution

It provides the NLO staggered chiral perturbation theory formulation accounting for taste-breaking effects in $B o D^* l u$ form factor calculations.

Findings

Derived the NLO SChPT expressions for $B o D^* l u$

Clarified the impact of taste-breaking discretization effects

Facilitated more accurate lattice QCD determinations of |V_{cb}|

Abstract

An unquenched calculation of the form factor for $B\to D^* l \nu$ is needed to improve the determination of $|V_{cb}|$. The MILC lattices, computed with a 2+1 improved staggered action for the light quarks, are well suited to this purpose. The relevant staggered chiral perturbation theory (SChPT) must be known in order to correctly account for the "taste" breaking discretization effects associated with the staggered quarks to NLO in $1/ m_{D^*}$. This SChPT calculation is presented.