PRD 87, 071103(R) (2013)
LHCb:
INSPIRE
Parameter
Measurement
\(\frac{{\cal{B}} ( B_c^- \to \psi(2S) \pi^- ) } {{\cal{B}} ( B_c^- \to J/\psi \pi^- ) }\)
\([0.25 \pm 0.07\mbox{ (stat)} \pm 0.01\mbox{ (syst)} \pm 0.01\mbox{ (R(psi))}]\)