Вы находитесь на старом сайте НГУ. Перейти на новый сайт

ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2008, vol. 100, p. -

Measurement of B(Ds+→μ+νμ)

Widhalm L., Adachi I., Aihara H., Aushev T., Bakich A. M., Balagura V., Barberio E., Bay A., Bedny I., Bhardwaj V., Bitenc U., Blyth S., Bozek A., Bračko M., Brodzicka J., Browder T. E., Chao Y., Chen A., Chen W. T., Cheon B. G., Chistov R., Cho I. S., Choi Y., Dalseno J., Dash M., Drutskoy A., Eidelman S., Goldenzweig P., Golob B., Ha H., Haba J., Hayasaka K., Hayashii H., Hazumi M., Heffernan D., Hoshi Y., Hou W. S., Hsiung Y. B., Hyun H. J., Iijima T., Inami K., Ishikawa A., Ishino H., Itoh R., Iwasaki M., Iwasaki Y., Kah D. H., Kang J. H., Kapusta P., Katayama N., Kawai H., Kawasaki T., Kichimi H., Kim S. K., Kim Y. J., Kinoshita K., Korpar S., Križan P., Krokovny P., Kumar R., Kuo C. C., Kuroki Y., Kuzmin A., Kwon Y. J., Lee J., Lee J. S., Lee M. J., Lee S. E., Lesiak T., Lin S. W., Liu C., Liventsev D., Mandl F., Matyja A., McOnie S., Mitaroff W., Miyake H., Miyata H., Miyazaki Y., Mizuk R., Moloney G. R., Nakano E., Nakao M., Natkaniec Z., Nishida S., Nitoh O., Noguchi S., Ogawa S., Ohshima T., Okuno S., Ozaki H., Pakhlov P., Pakhlova G., Palka H., Park C. W.

We present a measurement of the branching fraction B(Ds+→μ+νμ ) using a 548fb-1 data sample collected by the Belle experiment at the KEKB e+e- collider. The Ds momentum is determined by reconstruction of the system recoiling against DKγX in events of the type e+e-→Ds*DKX, Ds*→Dsγ, where X represents additional pions or photons from fragmentation. This full-reconstruction method provides high resolution in the neutrino momentum and thus good background separation, equivalent to that achieved by experiments at the tau-charm factories. We obtain the branching fraction B(Ds+→μ+νμ)=[6.44±0.76(stat)±0.57(syst)] ×10-3, implying a Ds decay constant of fDs=[275±16(stat) ±12(syst)]MeV. © 2008 The American Physical Society.