Effect of Magnetic Fields on Charged B Meson Decays

The effect of magnetic fields on the leptonic decay of charged B meson B− → l-v- is investigated. The decay rate of the process is calculated both in the absence and presence of magnetic field. The non-perturbative parameters fB± (B), f'B± and MB±(B) are also estimated.

A SEARCH FOR B→τν

We report results of a search for B→τν in a sample of 9.7 million charged B meson decays. The search uses both πν and [Formula: see text] decay modes of the τ, and demands exclusive reconstruction of the companion [Formula: see text] decay to suppress background. We set an upper limit on the branching fraction ℬ(B→τν)<8.4×10-4 at 90% confidence level. With slight modification to the analysis we also establish [Formula: see text] at 90% confidence level.