Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-

TL;DR

This paper reports evidence that the psi(3770) particle decays into a non-D anti-D final state, specifically to J/psi pi+pi-, with quantified branching fraction and partial width based on experimental data.

Contribution

First experimental evidence of psi(3770) decaying to J/psi pi+pi- with measured branching fraction and partial width.

Findings

Evidence of non-D D-bar decay mode of psi(3770)

Branching fraction measured at (0.34 ± 0.14 ± 0.09)%

Partial width estimated at (80 ± 33 ± 23) keV

Abstract

Evidence of $\psi(3770)$ decays to a non-${D \bar D}$ final state is observed. A total of $11.8 \pm 4.8 \pm 1.3$ $\psi(3770) \to \PPJP$ events are obtained from a data sample of 27.7 $\rm {pb^{-1}}$ taken at center-of-mass energies around 3.773 GeV using the BES-II detector at the BEPC. The branching fraction is determined to be $BF(\psi(3770) \to \PPJP)=(0.34\pm 0.14 \pm 0.09)%$, corresponding to the partial width of $\Gamma(\psi(3770) \to \PPJP) = (80 \pm 33 \pm 23)$ keV.