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arXiv · 1005.5177

Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference ΔΓ_s

S. Esen·A. J. Schwartz·I. Adachi·H. Aihara·K. Arinstein·V. Aulchenko·T. Aushev·T. Aziz·A. M. Bakich·V. Balagura·E. Barberio·A. Bay·M. Bischofberger·A. Bondar·A. Bozek·M. Bracko·T. E. Browder·M. -C. Chang·P. Chang·A. Chen·P. Chen·B. G. Cheon·C. -C. Chiang·Y. Choi·J. Dalseno·M. Dash·Z. Dolezal·Z. Drasal·A. Drutskoy·S. Eidelman·P. Goldenzweig·B. Golob·H. Ha·J. Haba·T. Hara·K. Hayasaka·T. Higuchi·Y. Hoshi·W. -S. Hou·Y. B. Hsiung·H. J. Hyun·T. Iijima·K. Inami·R. Itoh·M. Iwabuchi·N. J. Joshi·T. Julius·J. H. Kang·T. Kawasaki·H. Kichimi·H. J. Kim·H. O. Kim·J. H. Kim·Y. J. Kim·K. Kinoshita·B. R. Ko·P. Kodys·S. Korpar·P. Krizan·P. Krokovny·T. Kuhr·T. Kumita·Y. -J. Kwon·S. -H. Kyeong·J. S. Lange·S. -H. Lee·Y. Liu·D. Liventsev·R. Louvot·A. Matyja·S. McOnie·H. Miyata·R. Mizuk·G. B. Mohanty·E. Nakano·M. Nakao·H. Nakazawa·Z. Natkaniec·S. Neubauer·S. Nishida·O. Nitoh·T. Ohshima·S. Okuno·S. L. Olsen·P. Pakhlov·C. W. Park·H. Park·H. K. Park·M. Petric·L. E. Piilonen·M. Rohrken·S. Ryu·H. Sahoo·Y. Sakai·O. Schneider·C. Schwanda·K. Senyo·M. E. Sevior·M. Shapkin·C. P. Shen
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Abstract

We have made the first observation of Bs->Ds(*)+Ds(*)- decays using 23.6 fb-1 of data recorded by the Belle experiment running on the Upsilon(5S) resonance. The branching fractions are measured to be B(B^0_s\ra D^+_s D^-_s) = (1.0\,^{+0.4}_{-0.3}\,^{+0.3}_{-0.2})%, B(B^0_s\ra D^{*\pm}_s D^{\mp}_s) = (2.8\,^{+0.8}_{-0.7}\,\pm 0.7)%, and B(B^0_s\ra D^{*+}_s D^{*-}_s) = (3.1\,^{+1.2}_{-1.0}\,\pm 0.8)%; the sum is B(B^0_s\ra D^{(*)+}_s D^{(*)-}_s) = (6.9\,^{+1.5}_{-1.3}\,\pm 1.9)%. Assuming Bs->Ds(*)+Ds(*)- saturates decays to CP-even final states, the branching fraction determines the ratio ΔΓ_s/cos(ϕ), where ΔΓ_s is the difference in widths between the two Bs-Bsbar mass eigenstates, and ϕis a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain ΔΓ_s/Γ_s = 0.147^{+0.036}_{-0.030}(stat.)^{+0.044}_{-0.042}(syst.), where Γ_s is the mean decay width.

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S. Esen, A. J. Schwartz, I. Adachi, H. Aihara, K. Arinstein, V. Aulchenko, T. Aushev, T. Aziz, A. M. Bakich, V. Balagura, E. Barberio, A. Bay, M. Bischofberger, A. Bondar, A. Bozek, M. Bracko, T. E. Browder, M. -C. Chang, P. Chang, A. Chen, P. Chen, B. G. Cheon, C. -C. Chiang, Y. Choi, J. Dalseno, M. Dash, Z. Dolezal, Z. Drasal, A. Drutskoy, S. Eidelman, P. Goldenzweig, B. Golob, H. Ha, J. Haba, T. Hara, K. Hayasaka, T. Higuchi, Y. Hoshi, W. -S. Hou, Y. B. Hsiung, H. J. Hyun, T. Iijima, K. Inami, R. Itoh, M. Iwabuchi, N. J. Joshi, T. Julius, J. H. Kang, T. Kawasaki, H. Kichimi, H. J. Kim, H. O. Kim, J. H. Kim, Y. J. Kim, K. Kinoshita, B. R. Ko, P. Kodys, S. Korpar, P. Krizan, P. Krokovny, T. Kuhr, T. Kumita, Y. -J. Kwon, S. -H. Kyeong, J. S. Lange, S. -H. Lee, Y. Liu, D. Liventsev, R. Louvot, A. Matyja, S. McOnie, H. Miyata, R. Mizuk, G. B. Mohanty, E. Nakano, M. Nakao, H. Nakazawa, Z. Natkaniec, S. Neubauer, S. Nishida, O. Nitoh, T. Ohshima, S. Okuno, S. L. Olsen, P. Pakhlov, C. W. Park, H. Park, H. K. Park, M. Petric, L. E. Piilonen, M. Rohrken, S. Ryu, H. Sahoo, Y. Sakai, O. Schneider, C. Schwanda, K. Senyo, M. E. Sevior, M. Shapkin, C. P. Shen. 2010-12-08. Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference ΔΓ_s. https://doi.org/10.1103/physrevlett.105.201802

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