We present searches for the leptonic decays B+-> l(+)nu and the lepton flavor violating decays B-0 -> l(+/-)tau(-/+), where l = e, mu, with data collected by the BABAR experiment at SLAC. This search demonstrates a novel technique in which we fully reconstruct the accompanying (B) over bar in Gamma(4S)-> B (B) over bar events, and look for a monoenergetic lepton from the signal B decay. The signal yield is extracted from a fit to the signal lepton candidate momentum distribution in the signal B rest frame. Using a data sample of approximately 378x10(6) B (B) over bar pairs (342 fb(-1)), we find no evidence of signal in any of the decay modes. Branching fraction upper limits of B(B+ -> e(+)nu) < 5.2 x 10(-6), B(B+ -> mu(+)nu) < 5.6 x 10(-6), B(B-0 -> e(+)tau(-)) < 2.8 x 10(-5) and B(B-0 -> mu(+)tau(-)) < 2.2 x 10(-5), are obtained at 90\% confidence level.

Searches for the decays B-0 -> l(+/-)tau(-/+) and B+-> l(+)nu (l = e, mu) using hadronic tag reconstruction

BIANCHI, Fabrizio;GAMBA, Diego;
2008-01-01

Abstract

We present searches for the leptonic decays B+-> l(+)nu and the lepton flavor violating decays B-0 -> l(+/-)tau(-/+), where l = e, mu, with data collected by the BABAR experiment at SLAC. This search demonstrates a novel technique in which we fully reconstruct the accompanying (B) over bar in Gamma(4S)-> B (B) over bar events, and look for a monoenergetic lepton from the signal B decay. The signal yield is extracted from a fit to the signal lepton candidate momentum distribution in the signal B rest frame. Using a data sample of approximately 378x10(6) B (B) over bar pairs (342 fb(-1)), we find no evidence of signal in any of the decay modes. Branching fraction upper limits of B(B+ -> e(+)nu) < 5.2 x 10(-6), B(B+ -> mu(+)nu) < 5.6 x 10(-6), B(B-0 -> e(+)tau(-)) < 2.8 x 10(-5) and B(B-0 -> mu(+)tau(-)) < 2.2 x 10(-5), are obtained at 90\% confidence level.
2008
77
9
16
B. Aubert; M. Bona; Y. Karyotakis; J. P. Lees; V. Poireau; X. Prudent; V. Tisserand; A. Zghiche; J. Garra Tico; E. Grauges; L. Lopez; A. Palano; M. Pa...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/44828
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