Supersymmetric CP Violation in $B \to X_s l^+ l^-$ in Minimal Supergravity Model

TL;DR

This paper investigates CP violation effects in the inclusive decay B → X_s l^+ l^- within the minimal supergravity model, highlighting potential observable CP asymmetries and lepton polarizations influenced by CP violating phases and Higgs contributions.

Contribution

It provides a detailed analysis of CP violation and lepton polarization in B decays in the minimal supergravity model, including effects of neutral Higgs exchange and CP phases, which were not extensively studied before.

Findings

Direct CP violation in branching ratio is about 10^{-3}.

Lepton polarization can reach up to 0.5% for muons and a few percent for taus.

CP asymmetries are sensitive to CP violating phases and could be observed in future experiments.

Abstract

Direct CP asymmetries and the CP violating normal polarization of lepton in inclusive decay B \to X_s l^+ l^- are investigated in minimal supergravity model with CP violating phases. The contributions coming from exchanging neutral Higgs bosons are included. It is shown that the direct CP violation in branching ratio, A_{CP}^1, is of {\cal{O}}(10^{-3}) for l=e, \mu, \tau. The CP violating normal polarization for l=\mu can reach 0.5 percent when tan\beta is large (say, 36). For l=\tau and in the case of large \tan\beta, the direct CP violation in backward-forward asymmetry, A_{CP}^2, can reach one percent, the normal polarization of \tau can be as large as a few percent, and both are sensitive to the two CP violating phases, \phi_\mu and \phi_{A_0}, and consequently it could be possible to observe them (in particular, the normal polarization of \tau) in the future B factories.