Search for lepton-flavor and lepton-number-violating tau -˃ lhh ' decay modes

Abstract

We search for lepton-flavor and lepton-number-violating tau decays into a lepton (l = electron or muon) and two charged mesons (h, h' = pi(+/-) or K-+/-) using 854 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We obtain 90% confidence level upper limits on the tau -> lhh' branching fractions in the range (2.0-8.4) x 10(-8). These results improve upon our previously published upper limits by factors of about 1.8 on average. (c) 2013 Elsevier B.V. All rights reserved.