Вы находитесь на старом сайте НГУ. Перейти на новый сайт

ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2008, vol. 77, p. -

Search for B+→τ+ν decays with hadronic B tags

Aubert B., Bona M., Boutigny D., Karyotakis Y., Lees J. P., Poireau V., Prudent X., Tisserand V., Zghiche A., Tico J. Garra, Grauges E., Lopez L., Palano A., Pappagallo M., Eigen G., Stugu B., Sun L., Abrams G. S., Battaglia M., Brown D. N., Button-Shafer J., Cahn R. N., Groysman Y., Jacobsen R. G., Kadyk J. A., Kerth L. T., Kolomensky Yu G., Kukartsev G., Pegna D. Lopes, Lynch G., Mir L. M., Orimoto T. J., Osipenkov I. L., Ronan M. T., Tackmann K., Tanabe T., Wenzel W. A., Del Amo Sanchez P., Hawkes C. M., Watson A. T., Koch H., Schroeder T., Walker D., Asgeirsson D. J., Cuhadar-Donszelmann T., Fulsom B. G., Hearty C., Mattison T. S., McKenna J. A., Barrett M., Khan A., Saleem M., Teodorescu L., Blinov V. E., Bukin A. D., Druzhinin V. P., Golubev V. B., Onuchin A. P., Serednyakov S. I., Skovpen Yu I., Solodov E. P., Todyshev K. Yu, Bondioli M., Curry S., Eschrich I., Kirkby D., Lankford A. J., Lund P., Mandelkern M., Martin E. C., Stoker D. P., Abachi S., Buchanan C., Foulkes S. D., Gary J. W., Liu F., Long O., Shen B. C., Vitug G. M., Zhang L., Paar H. P., Rahatlou S., Sharma V., Berryhill J. W., Campagnari C., Cunha A., Dahmes B., Hong T. M., Kovalskyi D., Richman J. D., Beck T. W., Eisner A. M., Flacco C. J., Heusch C. A., Kroseberg J., Lockman W. S., Schalk T., Schumm B. A., Seiden A., Wilson M. G.

We present a search for the decay B+→τ+ν using 383×106 BB̄ pairs collected at the Υ(4S) resonance with the BABAR detector at the SLAC PEP-II B Factory. We select a sample of events with one completely reconstructed tag B in a hadronic decay mode (B-→D(*)0X-), and examine the rest of the event to search for a B+→τ+ν decay. We identify the τ lepton in the following modes: τ+→e+νν̄, τ+→μ+νν̄, τ+→π+ν̄, and τ+→π+π0ν̄. We find a 2.2σ excess in data and measure a branching fraction of B(B+→τ+ν)=(1.8-0.8+0.9(stat.) ±0.4(bkg.syst.)±0.2(othersyst.))×10-4. We calculate the product of the B meson decay constant fB and |Vub| to be fB•|Vub|=(10.1-2. 5+2.3(stat.)-1.5+1.2(syst.))×10-4GeV. © 2008 The American Physical Society.