Search for Lepton-Flavor-Violating Decays of B Mesons

TL;DR

This study searched for rare lepton-flavor-violating decays of B mesons in a large dataset but found no evidence, setting upper limits on their branching fractions to constrain new physics models.

Contribution

The paper provides the first comprehensive search for multiple lepton-flavor-violating B meson decays and establishes upper limits on their branching fractions.

Findings

No evidence for lepton-flavor-violating decays was observed.

Upper limits on branching fractions range from 1.0 to 8.3 x 10^{-6}.

Results constrain theories predicting such rare decays.

Abstract

We have searched a sample of 9.6 million BB-bar events for the lepton-flavor-violating decays B --> h e^{+-} mu^{-+}, B^+ --> h^- e^+ e^+, B^+ --> h^- e^+ mu^+, and B^+ --> h^- mu^+ mu^+, where h is pi, K, rho, and K*(892), a total of sixteen modes. We find no evidence for these decays, and place 90% confidence level upper limits on their branching fractions that range from 1.0 to 8.3 X 10^{-6}.