Вы находитесь на старом сайте НГУ. Перейти на новый сайт

ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2016, vol. 93, 11, p. -

First observation of γγ →p p K+K- and search for exotic baryons in pK systems

Shen C. P., Yuan C. Z., Adachi I., Aihara H., Asner D. M., Aulchenko V., Aushev T., Ayad R., Babu V., Badhrees I., Bakich A. M., Barberio E., Behera P., Bhardwaj V., Bhuyan B., Biswal J., Bobrov A., Bonvicini G., Bozek A., Bračko M., Browder T. E., Červenkov D., Chang P., Chekelian V., Chen A., Cheon B. G., Chilikin K., Chistov R., Cho K., Chobanova V., Choi S. K., Choi Y., Cinabro D., Dalseno J., Danilov M., Dash N., DoleŽal Z., Drásal Z., Dutta D., Eidelman S., Fang W. X., Fast J. E., Ferber T., Fulsom B. G., Gaur V., Gabyshev N., Garmash A., Gillard R., Glattauer R., Goldenzweig P., Grzymkowska O., Haba J., Hayasaka K., Hayashii H., Hou W. S., Iijima T., Inami K., Inguglia G., Ishikawa A., Itoh R., Iwasaki Y., Jaegle I., Jeon H. B., Joo K. K., Julius T., Kang K. H., Kato E., Kiesling C., Kim D. Y., Kim J. B., Kim K. T., Kim S. H., Kim Y. J., Kodyš P., Korpar S., Kotchetkov D., KriŽan P., Krokovny P., Kuzmin A., Kwon Y. J., Lange J. S.

© 2016 American Physical Society.The process γγ→ppK+K- and its intermediate processes are measured for the first time using a 980 fb-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The production of ppK+K- and a Λ(1520)0 (Λ(1520)0) signal in the pK- (pK+) invariant mass spectrum are clearly observed. However, no evidence for an exotic baryon near 1540 MeV/c2, denoted as Θ(1540)0 (Θ(1540)0) or Θ(1540)++ (Θ(1540) - ), is seen in the pK- (pK+) or pK+ (pK-) invariant mass spectra. Cross sections for γγ→ppK+K-, Λ(1520)0pK++c.c. and the products σ(γγ→Θ(1540)0pK++c.c.)B(Θ(1540)0→pK-) and σ(γγ→Θ(1540)++pK-+c.c.)B(Θ(1540)++→pK+) are measured. We also determine upper limits on the products of the χc0 and χc2 two-photon decay widths and their branching fractions to ppK+K- at the 90% credibility level.