Evidence for B+ {yields} {tau}+{nu}{tau} decays and measurement of fB from Belle

Journal Article · Tue Feb 27 00:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2714406· OSTI ID:21056844

Kwon, Youngjoon ^[1]

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1. Dept. of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of)

We present the first evidence for B+ {yields} {tau}+{nu}{tau} decay, using 414 fb-1 of B meson decay event sample collected with the Belle detector at the KEKB e+e- collider. To cope with large missing energy due to multiple neutrinos in the final state, events are tagged by fully reconstructing one of the B mesons. We find the evidence for signal with a significance of 3.5 {sigma} including systematic uncertainties. The branching fraction is measured to be B(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) (1.79{sub -0.49-0.51}{sup +0.56+0.46}) x 10{sup -4}. From this we obtain f{sub B} = 0.229{sub -0.031-0.037}{sup +0.036+0.034} GeV, the first direct determination of the B meson decay constant.

• OSTI ID: 21056844
• Journal Information: AIP Conference Proceedings, Vol. 892, Issue 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714406; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA). Belle Collaboration; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B PLUS MESONS
BRANCHING RATIO
DECAY AMPLITUDES
ELECTRON-POSITRON INTERACTIONS
GEV RANGE
LEPTONIC DECAY
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
TAU NEUTRINOS
TAU PARTICLES