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arXiv · 1208.0323

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

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
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Abstract

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.

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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. 2013-07-13. Precise measurement of the branching fractions for Bs->Ds(*)+ Ds(*)- and first measurement of the Ds*+ Ds*- polarization using e+e- collisions. https://doi.org/10.1103/physrevd.87.031101

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