Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference \Delta\Gamma_s
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 \Delta\Gamma_s/cos(\phi), where \Delta\Gamma_s is the difference in widths between the two Bs-Bsbar mass eigenstates, and \phi is a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain \Delta\Gamma_s/\Gamma_s = 0.147^{+0.036}_{-0.030}(stat.)^{+0.044}_{-0.042}(syst.), where \Gamma_s is the mean decay width.
Keywords
Cite
@article{arxiv.1005.5177,
title = {Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference \Delta\Gamma_s},
author = {S. Esen and A. J. Schwartz and I. Adachi and H. Aihara and K. Arinstein and V. Aulchenko and T. Aushev and T. Aziz and A. M. Bakich and V. Balagura and E. Barberio and A. Bay and M. Bischofberger and A. Bondar and A. Bozek and M. Bracko and T. E. Browder and M. -C. Chang and P. Chang and A. Chen and P. Chen and B. G. Cheon and C. -C. Chiang and Y. Choi and J. Dalseno and M. Dash and Z. Dolezal and Z. Drasal and A. Drutskoy and S. Eidelman and P. Goldenzweig and B. Golob and H. Ha and J. Haba and T. Hara and K. Hayasaka and T. Higuchi and Y. Hoshi and W. -S. Hou and Y. B. Hsiung and H. J. Hyun and T. Iijima and K. Inami and R. Itoh and M. Iwabuchi and N. J. Joshi and T. Julius and J. H. Kang and T. Kawasaki and H. Kichimi and H. J. Kim and H. O. Kim and J. H. Kim and Y. J. Kim and K. Kinoshita and B. R. Ko and P. Kodys and S. Korpar and P. Krizan and P. Krokovny and T. Kuhr and T. Kumita and Y. -J. Kwon and S. -H. Kyeong and J. S. Lange and S. -H. Lee and Y. Liu and D. Liventsev and R. Louvot and A. Matyja and S. McOnie and H. Miyata and R. Mizuk and G. B. Mohanty and E. Nakano and M. Nakao and H. Nakazawa and Z. Natkaniec and S. Neubauer and S. Nishida and O. Nitoh and T. Ohshima and S. Okuno and S. L. Olsen and P. Pakhlov and C. W. Park and H. Park and H. K. Park and M. Petric and L. E. Piilonen and M. Rohrken and S. Ryu and H. Sahoo and Y. Sakai and O. Schneider and C. Schwanda and K. Senyo and M. E. Sevior and M. Shapkin and C. P. Shen and J. -G. Shiu and P. Smerkol and E. Solovieva and M. Staric and K. Sumisawa and T. Sumiyoshi and Y. Teramoto and K. Trabelsi and S. Uehara and Y. Unno and S. Uno and P. Urquijo and Y. Usov and G. Varner and K. E. Varvell and K. Vervink and C. H. Wang and M. -Z. Wang and P. Wang and Y. Watanabe and R. Wedd and J. Wicht and E. Won and B. D. Yabsley and Y. Yamashita and Z. P. Zhang and V. Zhilich and A. Zupanc},
journal= {arXiv preprint arXiv:1005.5177},
year = {2010}
}
Comments
13 pages, 2 figures, 2 tables. v2: text added for clarification, version published in Phys. Rev. Letters