PRL 92 241802 (2004)

BaBar: INSPIRE link

ParameterMeasurement
\(\frac{{\cal{B}} ( B^- \to J/\psi(1S) \pi^- )}{{\cal{B}} ( B^- \to J/\psi(1S) K^- )}\)\([0.0537 \pm 0.0045\mbox{ (stat)} \pm 0.0011\mbox{ (syst)}]\)
\({\cal{B}} ( B^- \to J/\psi \pi^- )\)\([0.537 \pm 0.045\mbox{ (stat)} \pm 0.024\mbox{ (syst)}] \times 10^{-4}\)