Title: First Observation of Br(Bs --> Ds K)/Br(Bs --> Ds pi): Towards Measuring gamma in the Bs Sector


The Bs meson decays to two final states containing a Ds and K meson: Bs0 --> Ds+ K- and Bs0 --> Ds- K+. Both decay diagrams are proportional to the same power of the Cabibbo angle, and their relative weakphase is the CKM angle gamma. This talk will describe the first measurement of Br(Bs --> Ds K)/Br(Bs --> Ds pi), which was recently performed using the CDF II detector at the Fermilab Tevatron. We will conclude with a discussion of the prospects of using Bs --> Ds K decays to measure gamma in the future.