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arXiv · 0809.3834

Measurement of B- -> tau- nu_tau-bar Decay With a Semileptonic Tagging Method

The Belle Collaboration·I. Adachi
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Abstract

We present a new measurement of the decay B- -> tau- nu_tau-bar with a semileptonic B tagging method, using a data sample containing 657*10^6 BB-bar pairs collected at the (4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider. A sample of BB pairs are tagged by reconstructing one B meson decaying semileptonically. We detect the B- -> tau- nu_tau-bar candidate in the recoil. We obtain a signal with a signicance of 3.8 standard deviations including systematics, and measure the branching fraction to be B(B- -> tau- nu_tau-bar)=(1.65+0.38-0.37(stat)+0.35-0.37(syst))*10^4. This result confirms the evidence for B- -> tau- nu_tau-bartained in the previous Belle measurement with a hadronic B tagging method.

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The Belle Collaboration, I. Adachi. 2008-09-23. Measurement of B- -> tau- nu_tau-bar Decay With a Semileptonic Tagging Method. https://arxiv.org/abs/0809.3834

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