Search for the rare decay B0 → τ+τ- at B A B A R

We present the results of a search for the decay B0→τ+τ- in a data sample of (232±3)×106 Υ(4S)→BB decays using the BABAR detector. Certain extensions of the standard model predict measurable levels of this otherwise rare decay. We reconstruct fully one neutral B meson and seek evidence for the signal decay in the rest of the event. We find no evidence for signal events and obtain B(B0→τ+τ-)<4.1×10-3 at the 90% confidence level. © 2006 The American Physical Society.