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

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.