Measurement of the inclusive semileptonic branching fraction B(B-s(0) -?? X(-)l(+)v(l)) at Belle

We report a measurement of the inclusive semileptonic B-s(0) branching fraction in a 121 fb(-1) data sample collected near the Y(5S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. Events containing B-s(0(*))(B) over bar (0(*))(s) pairs are selected by reconstructing a tag side D-s(+) and identifying a signal side lepton l(+) (l = e, mu) that is required to have the same- sign charge to ensure that both originate from different B-s(0) mesons. The B-s(0) -?? X(-)l(+)v(l) branching fraction is extracted from the ratio of the measured yields of D-s(+) mesons and D(s)(+)l(+) pairs and the known production and branching fractions. The inclusive semileptonic branching fraction is measured to be [10.6 +/- 0.5(stat) +/- 0.7(syst)]%.We thank the KEKB group for the excellent operation of the accelerator; the KEK cryogenics group for the efficient operation of the solenoid; and the KEK computer group, the National Institute of Informatics, and the PNNL/EMSL computing group for valuable computing and SINET4 network support. We acknowledge support from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan, the Japan Society for the Promotion of Science (JSPS), and the Tau-Lepton Physics Research Center of Nagoya University; the Australian Research Council and the Australian Department of Industry, Innovation, Science and Research; the National Natural Science Foundation of China under Contracts No. 10575109, No. 10775142, No. 10875115, and No. 10825524; the Ministry of Education, Youth and Sports of the Czech Republic under Contracts No. LA10033 and No. MSM0021620859; the Department of Science and Technology of India; the Istituto Nazionale di Fisica Nucleare of Italy; the BK21 and WCU program of the Ministry of Education, Science and Technology, National Research Foundation of Korea, and GSDC of the Korea Institute of Science and Technology Information; the Polish Ministry of Science and Higher Education; the Ministry of Education and Science of the Russian Federation and the Russian Federal Agency for Atomic Energy; the Slovenian Research Agency; the Swiss National Science Foundation; the National Science Council and the Ministry of Education of Taiwan; and the U.S. Department of Energy and the National Science Foundation. This work is supported by a Grant-in-Aid from MEXT for Science Research in a Priority Area ("New Development of Flavor Physics''), and from JSPS for Creative Scientific Research ("Evolution of Tau-lepton Physics")