Physics Commons^™

Observation Of Τ−→Π−ΝΤE+E− And Search For Τ−→Π−Ντμ+Μ−, Y. Jin, H. Aihara, D. Epifanov, I. Adachi, S. Ai. Said, D. M. Asner, V. Aulchenko, T. Aulchenko, T. Aushev, R. Ayad, V. Babu, I. Badhrees, S. Bahinipati, V. Bansal, P. Behera, M. Berger, V. Bhardwaj, T. Bilka, J. Biswal, Milind Purohit, Et. Al.

Faculty Publications

We present the first measurements of branching fractions of rare tau-lepton decays, τ−→π−ντℓ+ℓ− (ℓ=e or μ), using a data sample corresponding to 562 fb⁻¹ collected at a center-of-mass energy of 10.58 GeV with the Belle detector at the KEKB asymmetric-energy e⁺e⁻collider. The τ−→π⁻ν_τe⁺e⁻ decay is observed for the first time with 7.0σ significance. The partial branching fraction determined by the structure-dependent mechanisms mediated by either a vector or an axial-vector current for the mass region M_πee > 1.05 GeV=c² is measured to be B(τ⁻ → π …