Search for the Rare Decay B0→τ+τ− at BABAR

Abstract

We present the results of a search for the decay B 0 → τ + τ − in a data sample of ( 232 ± 3 ) × 10 6 Υ ( 4 S ) → B ¯¯¯ B 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 ( B 0 → τ + τ − ) < 4.1 × 10 − 3 at the 90% confidence level.