A Search for B+ to mu+ nu_mu

TL;DR

This paper reports a search for the rare leptonic decay B+ to mu+ nu_mu using BABAR data, setting an upper limit on its branching fraction due to lack of observed signal.

Contribution

The study provides the first upper limit on the branching fraction of B+ to mu+ nu_mu using BABAR data at the Upsilon(4S) resonance.

Findings

No significant signal observed for B+ to mu+ nu_mu.

Set an upper limit on the branching fraction at 6.6 x 10^{-6}.

Data corresponds to 88.4 million BBbar pairs.

Abstract

We have performed a search for the leptonic B decay B+ --> mu+ nu_mu with data collected at the Upsilon(4S) resonance by the BABAR experiment at the PEP-II storage ring. With an integrated luminosity of approximately 81.4 fb-1 (88.4 million BBbar pairs), we find no convincing evidence for a signal and set a preliminary upper limit on the branching fraction of BR(B+ --> mu+ nu_mu) < 6.6 x 10^{-6} at the 90% confidence level.