Вы находитесь на старом сайте НГУ. Перейти на новый сайт

Observation of a resonance-like structure in the π ±ψ' mass distribution in exclusive B → Kπ±ψ' decays

Choi S. K., Olsen S. L., Adachi I., Aihara H., Aulchenko V., Aushev T., Aziz T., Bakich A. M., Balagura V., Bedny I., Bitenc U., Bondar A., Bozek A., Bracko M., Brodzicka J., Browder T. E., Chang P., Chao Y., Chen A., Chen K. F., Chen W. T., Cheon B. G., Chistov R., Choi Y., Dalseno J., Danilov M., Dash M., Eidelman S., Gabyshev N., Golob B., Haba J., Hara T., Hayasaka K., Hayashii H., Hazumi M., Heffernan D., Hoshi Y., Hou W. S., Hyun H. J., Iijima T., Inami K., Ishikawa A., Ishino H., Itoh R., Iwasaki M., Iwasaki Y., Kah D. H., Kang J. H., Katayama N., Kawai H., Kawasaki T., Kichimi H., Kim H. O., Kim S. K., Kim Y. J., Kinoshita K., Krizan P., Krokovny P., Kumar R., Kuo C. C., Kuzmin A., Kwon Y. J., Lange J. S., Lee J. S., Lee M. J., Lee S. E., Lesiak T., Limosani A., Lin S. W., Liu Y., Liventsev D., Mandl F., Matyja A., McOnie S., Medvedeva T., Mitaroff W., Miyabayashi K., Miyake H., Miyata H., Miyazaki Y., Mizuk R., Moloney G. R., Nakano E., Nakao M., Nishida S., Nitoh O., Nozaki T., Ogawa S., Ohshima T., Okuno S., Ozaki H., Pakhlov P., Pakhlova G., Park C. W., Park H.

A distinct peak is observed in the π±ψ' invariant mass distribution near 4.43 GeV in B → Kπ±ψ' decays. A fit using a Breit-Wigner resonance shape yields a peak mass and width of M = 4433 ± 4 (stat) ± 2 (syst) MeV and F = 45+18 -13 (stat)+30-13 (syst) MeV. The product branching fraction is determined to be B(B0 → K±Z± (4430)) × B(Z±(4430) → π±ψ') = (4.1 ± 1.0(stat) ± 1.4(syst)) × 10-5, where Z±(4430) is used to denote the observed structure. The statistical significance of the observed peak is 6.5σ. These results are obtained from a 605 fb-1 data sample that contains 657 million B ̄B pairs collected near the γ(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider.