PRL 114, 132001 (2015)
LHCb:
INSPIRE
Parameter
Measurement
\(\frac{{\sigma(B_c^{-}) \times \cal{B}} ( B_c^{-} \to J/\psi \pi^{-} )} {\sigma(B^{-}) \times {\cal{B}} ( B^{-} \to J/\psi K^{-} )}\)
\([0.683 \pm 0.018\mbox{ (stat)} \pm 0.009\mbox{ (syst)}] \times 10^{-2}\)