Angular analyses of exclusive $\overline{B} \to X_J \ell_1 \ell_2$ decays for spin $J \leq 4$

TL;DR

This paper extends the calculation of angular moments in exclusive B meson decays to systems with spin up to 4, aiding analysis of higher resonances in experiments like LHCb and Belle II.

Contribution

The paper provides updated angular moments calculations for $ar{B} o X_J \, \ell_1 \ell_2$ decays with $J \leq 4$, including consistency relations for $J \leq 2$ validated with recent data.

Findings

Angular moments for $J \leq 4$ in B decays are now available.

Consistency relations for $J \leq 2$ are validated with LHCb data.

Applications include analysis of higher resonances in LHCb and Belle II experiments.

Abstract

As an update to our previous calculation for spin $J\leq2$, we present the angular moments for exclusive $\overline{B} \to X_J \ell_1 \ell_2$, where $\ell_1$ is a charged massless lepton and $\ell_2$ is a charged or neutral massless lepton, and $X_J$ is a mesonic system with spin $J\leq4$. The expected applications include higher resonances in the $[K\pi]$ system in $\overline{B}^0 \to K^- \pi^+ \mu^- \mu^+$ at LHCb in Run~II, and in the $[\pi \pi]$ system for $ \overline{B} \to \pi \pi \ell^- \bar{\nu}_\ell$ at Belle~II. For the $J\leq2$ case, we also provide a set of consistency relations among the measured moments observables and validate them against the latest measurements from LHCb.