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

Abstract

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)]%.