B_s decays at Belle

Abstract

We report recent results obtained with the Belle detector using a 23.6 fb^{-1} data sample collected on the Y(5S) resonance at the KEKB asymmetric energy e^+ e^- collider. Inclusive semileptonic B_s^0 -> X^+ l^- νdecays are studied for the first time and the branching fraction is measured. Combining the electron and muon channels, we obtain Bf(B_s^0 -> X^+ l^- ν) = (10.2 \pm 0.8 \pm 0.9)%. Also, the radiative penguin decay B_s^0 -> ϕγis observed for the first time, and an improved upper limit for the decay B_s^0 \to γγis obtained.

Proceedings of the EPS/HEP 2007 Conference, Manchester, England, July 2007 (on behalf of the Belle collaboration), 3 pages, 2 figures