Вы находитесь на старом сайте НГУ. Перейти на новый сайт

ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2007, vol. 98, p. -

Evidence for B0→ρ0ρ0 decays and implications for the Cabibbo-Kobayashi-Maskawa angle α

Aubert B., Bona M., Boutigny D., Karyotakis Y., Lees J. P., Poireau V., Prudent X., Tisserand V., Zghiche A., Grauges E., Palano A., Chen J. C., Qi N. D., Rong G., Wang P., Zhu Y. S., Eigen G., Ofte I., Stugu B., 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., Pripstein M., Roe N. A., Ronan M. T., Tackmann K., Wenzel W. A., Del Amo Sanchez P., Barrett M., Harrison T. J., Hart A. J., Hawkes C. M., Watson A. T., Held T., Koch H., Lewandowski B., Pelizaeus M., Peters K., Schroeder T., Steinke M., Boyd J. T., Burke J. P., Cottingham W. N., Walker D., Asgeirsson D. J., Cuhadar-Donszelmann T., Fulsom B. G., Hearty C., Knecht N. S., Mattison T. S., McKenna J. A., Khan A., Kyberd P., Saleem M., Sherwood D. J., 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., Bruinsma M., Chao 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., Zhang L., Hill E. J., Paar H. P., Rahatlou S.

We search for the decays B0→ρ0ρ0, B0→ρ0f0(980), and B0→f0(980)f0(980) in a sample of about 384×106 Υ(4S) →BB̄ decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at Stanford Linear Accelerator Center. We find evidence for B0→ρ0ρ0 with 3.5σ significance and measure the branching fraction B=(1.07±0.33±0.19)×10-6 and longitudinal polarization fraction fL=0.87±0.13±0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix unitarity angle α due to penguin contributions in B→ρρ decays is 18° at the 1σ level. We also set upper limits on the B0→ρ0f0(980) and B0→f0(980)f0(980) decay rates. © 2007 The American Physical Society.