JHEP09(2013)075

LHCb: INSPIRE

ParameterMeasurement
\(\frac{{\cal{B}}( B_c^{-} \to J/\psi K^{-})} { {\cal{B}}( B_c^{-} \to J/\psi \pi^{-})}\)\([0.069 \pm 0.019\mbox{ (stat)} \pm 0.005\mbox{ (syst)}]\)