A closer look at the extraction of $|V_{ub}|$ from $B\to \pi l\nu$

Abstract

To extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|V_{ub}|$, we have re-analyzed all the available inputs (data and theory) on the $B\to \pi l\nu$ decays including the newly available inputs on the form-factors from light cone sum rule (LCSR) approach. We have reproduced and compared the results with the procedure taken up by the Heavy Flavor Averaging Group (HFLAV), while commenting on the effect of outliers on the fits. After removing the outliers and creating a comparable group of data-sets, we mention a few scenarios in the extraction of $|V_{ub}|$. In all those scenarios, the extracted values of $|V_{ub}|$ are higher than that obtained by HFLAV. Our best results for $|V_{ub}{|}^{exc.}$ are $(3.88\pm 0.13)\times 10^{-3}$ and $(3.87\pm 0.13)\times 10^{-3}$ in frequentist and Bayesian approaches, respectively, which are consistent with that extracted from inclusive decays $|V_{ub}{|}^{inc}$ within $1\sigma$ confidence interval.

Two figures added, version accepted for publication in JHEP

References in corpus (4)

• $B\to \pi \ell \nu$ and $B_s\to K\ell \nu$ form factors and $|V_{ub}|$ from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks
• Inclusive semileptonic B decays and the determination of |V_ub|
• Can the differences in the determinations of $V_{ub}$ and $V_{cb}$ be explained by New Physics?
• Inclusive Measure of |V_ub| with the Analytic Coupling Model

Cited by in corpus (9)

• 50 Years of Quantum Chromodynamics
• Precision calculations of $B_{d,s}\to \pi ,K$ decay form factors in soft-collinear effective theory
• Form factors of $B\to \pi \ell \nu$ and a determination of $|V_{ub}|$ with Möbius domain-wall-fermions
• Padé approximants to $B\to \pi \ell {\nu }_{\ell }$ and $B_s\to K\ell {\nu }_{\ell }$ and determination of $|V_{ub}|$
• Extractions of $|V_{ub}|/|V_{cb}|$ from a combined study of the exclusive $b\to u(c)\ell {\nu }_{\ell }$ decays
• Loopy Determinations of $V_{ub}$ and $V_{cb}$
• Study of the $b\to d\ell \ell$ transitions in the Standard Model and test of New Physics sensitivities
• A closer look at observables from exclusive semileptonic $B\to (\pi ,\rho )\ell {\nu }_{\ell }$ decays
• $\frac{|V_{ub}|}{|V_{cb}|}$ and Quest for New Physics