Revisiting $B\to D \ell \nu$

TL;DR

This paper re-evaluates the extraction of the CKM matrix element |V_{cb}| from B→Dℓν decays, incorporating recent experimental and theoretical advances, and discusses form factor parameterizations and unitarity constraints.

Contribution

It provides a new determination of |V_{cb}| and R(D) using updated data and explores the impact of unitarity constraints on form factor parameterizations.

Findings

|V_{cb}|=40.49(97)×10^{-3} from B→Dℓν data

Predicted R(D)=0.299(3) consistent with experimental results

Analysis highlights importance of unitarity constraints in form factor fits

Abstract

We re-examine the determination of $|V_{cb}|$ from $B\to D \ell \nu$ in view of recent experimental and theoretical progress, discussing the parameterization of the form factors and studying the role played by the unitarity constraints. Our fit to experimental and lattice results for $B\to D \ell \nu$ gives $|V_{cb}|=40.49(97)\ 10^{-3}$ and to $R(D)= 0.299(3)$.