Evidence for B- -> tau- nu_bar with a Semileptonic Tagging Method
Abstract
We present a measurement of the decay B- -> tau- nu_bar using a data sample containing 657 million BB_bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. A sample of BB_bar pairs are tagged by reconstructing one B meson decaying semileptonically. We detect the B- -> tau- nu_bar candidate in the recoil. We obtain a signal with a significance of 3.6 standard deviations including systematic uncertainties, and measure the branching fraction to be Br(B- -> tau- nu_bar) = [1.54+0.38-0.37(stat)+0.29-0.31(syst)]*10^-4. This result confirms the evidence for B- -> tau- nu_bar obtained in a previous Belle measurement that used a hadronic B tagging method.
Keywords
Cite
@article{arxiv.1006.4201,
title = {Evidence for B- -> tau- nu_bar with a Semileptonic Tagging Method},
author = {The Belle collaboration and K. Hara and T. Iijima},
journal= {arXiv preprint arXiv:1006.4201},
year = {2010}
}
Comments
7 pages, 3 figures, corrected references, to appear in PRD-RC