Search for the Rare Leptonic Decay B+ --> mu+ nu_mu

TL;DR

This paper reports a search for the rare decay B+ --> mu+ nu_mu using BABAR data, setting an upper limit on its branching fraction due to no significant detection.

Contribution

First experimental search for B+ --> mu+ nu_mu decay at BABAR, establishing an upper limit on its branching fraction.

Findings

No significant signal detected.

Upper limit on BR(B+ --> mu+ nu_mu) < 6.6 x 10^{-6}.

Data from 88.4 million BBbar pairs used.

Abstract

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