PRL 103, 191802 (2009)

CDF: INSPIRE link

ParameterMeasurement
\(\frac{{\cal{B}} ( \bar{B}_s^{0} \to D_s^{+} K^{-} )}{{\cal{B}} ( \bar{B}_s^{0} \to D_s^{+} \pi^{-} )}\)\([0.097 \pm 0.018\mbox{ (stat)} \pm 0.009\mbox{ (syst)}] \times 10^{0}\)