Flavor SU(3) analysis of the charmless semileptonic $B \to PV\ell^+\nu_\ell$ decays

TL;DR

This paper uses flavor SU(3) symmetry to predict branching ratios for charmless B meson decays into pseudoscalar and vector mesons with leptons, providing theoretical estimates for future experimental tests.

Contribution

It introduces a comprehensive SU(3) analysis of various charmless B decay modes involving axial-vector, tensor, and excited vector resonances, predicting their branching ratios.

Findings

Most B to A lepton decay branching ratios are around 10^{-4} to 10^{-3}.

Branching ratios involving tensor and excited vector resonances are small.

Predictions are testable at BelleII and LHCb.

Abstract

All charmless $B \to PV\ell^+\nu_\ell$ ($P$ denotes the light pseudoscalar meson and $V$ denotes the vector meson) decays have not been experimentally observed to date, but some of them might be measured in the near future. The charmless $B \to PV\ell^+\nu_\ell$ decays with the axial-vector ($A$) resonance states, the tensor ($T$) resonance states and the excited vector ($V_{E,D}$) resonance states are studied based on flavor SU(3) analysis in this work, where $V_E$ contains $\{\rho(1450), K^*(1410), \omega(1420), \phi(1680)\}$ with quantum numbers $n^{2S+1}L_J=2^3S_1$ and $V_D$ contains $\{\rho(1700), K^*(1680), \omega(1650), \phi(2170)\}$ with quantum numbers $n^{2S+1}L_J=1^3D_1$. The hadronic amplitudes of the $B \to A/T \ell^+\nu_{\ell}$ decays are related by the nonperturbative parameters, and the branching ratio predictions of $B \to A/T/V_{E,D} \ell^+\nu_{\ell}$ are obtained, and then the branching ratios of the $B\to A(A\to PV)\ell^+\nu_\ell$, $B\to T(T\to PV)\ell^+\nu_\ell$, $B\to V_E(V_E\to PV)\ell^+\nu_\ell$ and $B\to V_D(V_D\to PV)\ell^+\nu_\ell$ are obtained by the narrow width approximation or further considering the width effects. We find that most branching ratios of the $B \to A \ell^+\nu_{\ell}$ decays and many branching ratios of the $B\to A(A\to PV)\ell^+\nu_\ell$ decays are on the order of $\mathcal{O}(10^{-4}-10^{-3})$, and all branching ratios with the tensor resonance states and the excited vector resonance states are small. Our results could be tested in the future BelleII and LHCb experiments.