Theoretical and Phenomenological Constraints on Form Factors for Radiative and Semi-Leptonic B-Meson Decays

TL;DR

This paper combines theoretical constraints and phenomenological data from Lattice QCD, sum rules, and dispersive bounds to analyze form factors in B-meson decays, focusing on systematic uncertainties and NLO corrections.

Contribution

It introduces a comprehensive analysis of B-meson decay form factors using series expansion parameterizations and provides NLO corrections for unitarity constraints.

Findings

Quantitative assessment of systematic uncertainties in form factor parameterizations

Implementation of NLO corrections to tensor current correlation functions

Enhanced understanding of form factors for radiative and semi-leptonic B decays

Abstract

We study transition form factors for radiative and rare semi-leptonic B-meson decays into light pseudoscalar or vector mesons, combining theoretical constraints and phenomenological information from Lattice QCD, light-cone sum rules, and dispersive bounds. We pay particular attention to form factor parameterisations which are based on the so-called series expansion, and study the related systematic uncertainties on a quantitative level. In this context, we also provide the NLO corrections to the correlation function between two flavour-changing tensor currents, which enters the unitarity constraints for the coefficients in the series expansion.