PRL 108, 251802 (2012)

Parameter	Measurement
\(\frac{{\cal{B}} ( B_c^{-} \to J/\psi \pi^{+} \pi^{-} \pi^{-} )} {{\cal{B}} ( B_c^{-} \to J/\psi \pi^{-} )}\)	\([2.41 \pm 0.30\mbox{ (stat)} \pm 0.33\mbox{ (syst)}]\)