Isospin extrapolation as a method to study inclusive $\bar{B} \to X_{s} \ell^{+}\ell^{-}$ decays

TL;DR

This paper introduces a new isospin symmetry-based method to study inclusive B meson decays involving a strange quark and lepton pairs, aiming to improve measurements at hadron colliders.

Contribution

The paper proposes a novel isospin extrapolation technique to reconstruct inclusive B decay rates from semi-inclusive signatures, enhancing experimental feasibility.

Findings

Fast simulation shows potential advantages over fully inclusive methods.

Method could enable measurements of branching fractions, lepton universality, and CP asymmetries.

Experimental benefits suggest feasibility at hadron colliders.

Abstract

A novel approach to reconstruct inclusive $\bar{B} \to X_{s} \ell^{+}\ell^{-}$ decays is presented. The method relies on isopsin symmetry to extrapolate the semi-inclusive signature $X_{b}\to K^{+} \ell^{+}\ell^{-} X$ to the fully inclusive rate in $B^{+}$ and $B^{0}$ decays. We investigate the possibility to measure branching fractions and other observables such as lepton universality ratios and $CP$ asymmetries. As a proof of concept, fast simulation is used to compare the $X_{b}\to K^{+} \ell^{+}\ell^{-} X$ signature with a fully inclusive approach. Several experimental advantages are seen which have the potential to make measurements of inclusive $\bar{B} \to X_{s} \ell^{+}\ell^{-}$ decays tractable at a hadron collider.