Evidence of the Purely Leptonic Decay $B^{-} \to τ^{-} {\bar{ν}}_{τ}$

22 December 2006

journal article
research article
Published by American Physical Society (APS) in Physical Review Letters

Vol. 97 (25) , 251802
https://doi.org/10.1103/physrevlett.97.251802

Abstract

We present the first evidence of the decay

B^{-} \to τ^{-} {\bar{ν}}_{τ}

, using

414 {fb}^{- 1}

of data collected at the

Υ (4 S)

resonance with the Belle detector at the KEKB asymmetric-energy

e^{+} e^{-}

collider. Events are tagged by fully reconstructing one of the

B

mesons in hadronic modes. We detect the signal with a significance of 3.5 standard deviations including systematics and measure the branching fraction to be

B (B^{-} \to τ^{-} {\bar{ν}}_{τ}) = ({1.79}_{- 0.49}^{+ 0.56} (stat)_{- 0.51}^{+ 0.46} (syst)) \times 10^{- 4}

. This implies that

f_{B} = {0.229}_{- 0.031}^{+ 0.036} (stat)_{- 0.037}^{+ 0.034} (syst) GeV

and is the first direct measurement of this quantity.

Keywords

All Related Versions

This publication has 11 references indexed in Scilit:

Search for the decayB+→τ+ντ
Physical Review D, 2006
$B$ -Meson Decay Constant from Unquenched Lattice QCD
Physical Review Letters, 2005
RECENT RESULTS FROM LATTICE CALCULATIONS
International Journal of Modern Physics A, 2005
Review of Particle Physics
Physics Letters B, 2004
Overview of the KEKB accelerators
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003
The Belle detector
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
$f_{B}$ and $f_{B_{s}}$ from QCD sum rules
Physical Review D, 2002
Enhanced charged Higgs boson effects in $B^{-} \to τ \bar{ν}, μ \bar{ν}$ and $b \to τ \bar{ν} + X$
Physical Review D, 1993
Reconstruction of B mesons
Physics Letters B, 1987
Physics with the Crystal Ball Detector
Annual Review of Nuclear and Particle Science, 1983

Evidence of the Purely Leptonic DecayB−→τ−ν¯τ

Abstract

Keywords

All Related Versions

Evidence of the Purely Leptonic Decay $B^{-} \to τ^{-} {\bar{ν}}_{τ}$