B Meson Decays with τ Leptons in the Final State

Abstract

We present measurements of B meson decays with τ leptons in the final state. These decays, while experimentally more challenging than those involving light leptons, provide enhanced sensitivity to physics beyond the Standard Model due to the large τ mass. We present measurements of the branching fractions of B − → τ − ν ¯ τ and B → D ( ∗ ) τ − ν ¯ τ , as well as searches for the forbidden decays B 0 → ℓ ± τ ∓ and B − → K − τ ± μ ∓ . These measurements are based on several hundred million e + e − → ϒ ( 4 S ) → B B ¯ events recorded with the BaBar detector at the PEP-II asymmetric-energy collider.