Observation of $B^+\rightarrow J/\psi 3\pi^+ 2\pi^-$ and $B^+\rightarrow \psi(2S) \pi^+\pi^+\pi^-$ decays

TL;DR

This paper reports the first observation of specific B+ meson decays into J/psi and psi(2S) with multiple pions, measuring their branching fractions relative to a known decay mode using LHCb data.

Contribution

The study provides the first observation and measurement of branching fractions for B+ decays into J/psi and psi(2S) with multiple pions, expanding understanding of B meson decay modes.

Findings

First observation of B+→J/ψ 3π+ 2π− and B+→ψ(2S) π+π+π− decays.

Measured branching fractions relative to B+→ψ(2S)K+ with statistical and systematic uncertainties.

Data collected at 7 and 8 TeV by LHCb with 3.0 fb−1 luminosity.

Abstract

The decays $B^+\rightarrow J/\psi 3\pi^+ 2\pi^-$ and $B^+\rightarrow \psi(2S) \pi^+\pi^+\pi^-$ are observed for the first time using a data sample corresponding to an integrated luminosity of $3.0fb^{-1}$, collected by the LHCb experiment in proton-proton collisions at the centre-of-mass energies of 7 and 8 TeV. The branching fractions relative to that of $B^+ \rightarrow \psi(2S)K^+$ are measured to be \begin{eqnarray*} \frac {\mathcal{B}\left(B^+\rightarrow J/\psi 3\pi^+ 2\pi^- \right)} {\mathcal{B}\left(B^+ \rightarrow \psi(2S)K^+ \right)} & = & \left(1.88\pm0.17\pm0.09\right)\times10^{-2}, \frac {\mathcal{B}\left(B^+\rightarrow \psi(2S) \pi^+\pi^+\pi^- \right)} {\mathcal{B}\left(B^+ \rightarrow \psi(2S)K^+ \right)} & = & \left(3.04\pm0.50\pm0.26\right)\times10^{-2}, \end{eqnarray*} where the first uncertainties are statistical and the second are systematic.