Search for the rare leptonic decay B+-->mu(+)nu(mu)

Area of Science:

• Particle Physics
• High Energy Physics
• Experimental Physics

Background:

• Rare B+ meson decays offer insights into fundamental particle physics.
• Leptonic decays, such as B+ to muon neutrino, are particularly sensitive to new physics beyond the Standard Model.
• Previous searches have constrained the branching fractions of such rare decays.

Purpose of the Study:

• To search for the rare leptonic decay B+ --> mu(+)nu(mu).
• To set an upper limit on the branching fraction of this decay using experimental data.
• To probe for potential new physics contributions to B+ meson decays.

Main Methods:

• Utilized data collected by the BABAR experiment at the PEP-II storage ring.
• Analyzed a sample of 88.4 x 10^6 BBbar meson pairs collected at the Upsilon(4S) resonance.
• Employed analysis techniques to identify and reconstruct the B+ --> mu(+)nu(mu) decay signature.

Main Results:

• No significant evidence for the B+ --> mu(+)nu(mu) signal was observed.
• An upper limit on the branching fraction was established at B(B+ --> mu(+)nu(mu)) < 6.6 x 10^-6.
• The result is reported at the 90% confidence level.

Conclusions:

• The absence of a signal places stringent constraints on the branching fraction of this rare decay.
• The findings contribute to the ongoing effort to test the Standard Model of particle physics.
• This measurement helps to limit the parameter space for potential new theoretical models.