First Observation of B[over-bar][subscript s][superscript 0]-->D[subscript s][superscript ±]K[superscript ∓] and Measurement of the Ratio of Branching Fractions B(B[over-bar][subscript s][superscript 0]-->D[subscript s][superscript ±]K[superscript ∓]/B([over-bar][subscript s][superscript 0]-->D[subscript s][superscript +] pi[superscript -])

• Main Authors: Bauer, Gerry P. (Contributor), Choudalakis, Georgios (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Hahn, Kristian Allan (Contributor), Henderson, C. (Contributor), Knuteson, Bruce O. (Contributor), Makhoul, K. (Contributor), Xie, Si (Contributor), Paus, Christoph M. E. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2010-05-20T20:02:06Z.
• Subjects: Article
• Online Access: Get fulltext

 A combined mass and particle identification fit is used to make the first observation of the decay B[over-bar] s0-->Ds±K∓ and measure the branching fraction of B[over-bar] s0-->Ds±K∓ relative to B[over-bar] s0-->Ds+pi-. This analysis uses 1.2  fb-1 integrated luminosity of pp[over-bar] collisions at [sqrt]s=1.96  TeV collected with the CDF II detector at the Fermilab Tevatron collider. We observe a B[over-bar] s0-->Ds±K∓ signal with a statistical significance of 8.1σ and measure B(B[over-bar] s0-->Ds±K∓)/B(B[over-bar] s0-->Ds+pi-)=0.097±0.018(stat)±0.009(syst).