1208.0323 (S. Esen et al.)

Precise measurement of the branching fractions for Bs->Ds(*)+ Ds(*)- and
first measurement of the Ds*+ Ds*- polarization using e+e- collisions    [PDF]

S. Esen, A. J. Schwartz, H. Aihara, D. M. Asner, T. Aushev, A. M. Bakich, K. Belous, B. Bhuyan, A. Bozek, M. Braçko, T. E. Browder, V. Chekelian, A. Chen, P. Chen, B. G. Cheon, K. Chilikin, R. Chistov, I. -S. Cho, K. Cho, Y. Choi, J. Dalseno, M. Danilov, Z. Dolezal, A. Drutskoy, S. Eidelman, M. Feindt, V. Gaur, J. Haba, T. Hara, H. Hayashii, Y. Horii, Y. Hoshi, W. -S. Hou, Y. B. Hsiung, H. J. Hyun, T. Iijima, A. Ishikawa, R. Itoh, M. Iwabuchi, Y. Iwasaki, T. Iwashita, T. Julius, J. H. Kang, T. Kawasaki, C. Kiesling, H. O. Kim, K. T. Kim, M. J. Kim, Y. J. Kim, K. Kinoshita, B. R. Ko, S. Koblitz, P. Kodys, S. Korpar, R. T. Kouzes, P. Kriczan, P. Krokovny, T. Kuhr, T. Kumita, Y. -J. Kwon, S. -H. Lee, J. Li, Y. Li, J. Libby, C. Liu, Y. Liu, D. Liventsev, R. Louvot, S. McOnie, H. Miyata, R. Mizuk, D. Mohapatra, A. Moll, N. Muramatsu, M. Nakao, H. Nakazawa, Z. Natkaniec, C. Ng, S. Nishida, K. Nishimura, O. Nitoh, T. Ohshima, S. Okuno, S. L. Olsen, Y. Onuki, G. Pakhlova, C. W. Park, H. Park, H. K. Park, T. K. Pedlar, R. Pestotnik, M. Petriç, L. E. Piilonen, M. Röhrken, S. Ryu, Y. Sakai, D. Santel, L. Santelj, T. Sanuki, Y. Sato, O. Schneider, C. Schwanda, K. Senyo, M. E. Sevior, M. Shapkin, T. -A. Shibata, J. -G. Shiu, B. Shwartz, A. Sibidanov, F. Simon, P. Smerkol, Y. -S. Sohn, A. Sokolov, E. Solovieva, S. Staniç, M. Stariç, T. Sumiyoshi, G. Tatishvili, Y. Teramoto, K. Trabelsi, T. Tsuboyama, M. Uchida, S. Uehara, T. Uglov, Y. Unno, S. Uno, S. E. Vahsen, P. Vanhoefer, G. Varner, C. H. Wang, M. -Z. Wang, P. Wang, Y. Watanabe, K. M. Williams, E. Won, J. Yamaoka, Y. Yamashita, Z. P. Zhang, V. Zhilich, V. Zhulanov

We have made a precise measurement of the absolute branching fractions of Bs->Ds(*)+ Ds(*)- decays using 121.4 fb-1 of data recorded by the Belle experiment running on the Upsilon(5S) resonance. The results are B(Bs0->Ds+ Ds-) = (0.58 +0.11 -0.09 +-0.13)%, B(Bs0->Ds*+- Ds-+) = (1.8 +-0.2 +-0.4)%, and B(Bs0->Ds*+ Ds*-) = (2.0 +-0.3 +-0.5)%; the sum is B(Bs0->Ds(*)+ Ds(*)- = (4.3 +-0.4 +-1.0)%. Assuming Bs->Ds(*)+ Ds(*)- saturates decays to CP-even final states, the branching fraction constrains the ratio Delta(Gamma_s)/cos(phi_s), where Delta(Gamma_s) is the difference in widths between the two Bs0-Bs0bar mass eigenstates, and phi_s is the CP-violating phase in Bs0-Bs0bar mixing. For phi_s=0 we obtain Delta(Gamma_s)/Gamma_s = 0.090 +-0.009 (stat.) +-0.023 (syst.), where Gamma_s is the mean decay width. We also measure for the first time the longitudinal polarization fraction of Bs->Ds*+ Ds*-; the result is 0.12 +0.30 -0.28 +0.04 -0.05.

View original: http://arxiv.org/abs/1208.0323