Complete One-Loop MSSM Predictions for B --> lepton lepton' at the Tevatron and LHC

TL;DR

This paper provides comprehensive one-loop MSSM predictions for B meson decays into lepton pairs at the Tevatron and LHC, analyzing how these rates can be enhanced or suppressed across different parameter regions.

Contribution

It offers the first complete one-loop MSSM calculation for B --> l+l' decays, including arbitrary flavor mixing and various tan(beta) regimes.

Findings

Potential for significant suppression of decay rates below Standard Model predictions.

Identification of parameter regions with cancellation effects reducing observable signals.

Analysis applicable to both high and low tan(beta) scenarios.

Abstract

During the last few years the Tevatron has dramatically improved the bounds on rare B-meson decays into two leptons. In the case of B_s --> mu+ mu-, the current bound is only ten times greater than the Standard Model expectation. Sensitivity to this decay is one of the benchmark goals for LHCb performance and physics. The Higgs penguin dominates this rate in the region of large tan(beta) of the MSSM. This is not necessarily the case in the region of low tan(beta), since box and Z-penguin diagrams may contribute at a comparable rate. In this article, we compute the complete one-loop MSSM contribution to B --> l+l'- for l,l' = e, mu. We study the predictions for general values of tan(beta) with arbitrary flavour mixing parameters. We discuss the possibility of both enhancing and suppressing the branching ratios relative to their Standard Model expectations. In particular, we find that there are "cancellation regions" in parameter space where the branching ratio is suppressed well below the Standard Model expectation, making it effectively invisible to the LHC.