Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta

TL;DR

This paper reports the first measurements of the branching fractions for J/psi decays into 2(pi+pi-)eta and 3(pi+pi-)eta using a large sample of BESII detector data, providing new quantitative insights into these decay modes.

Contribution

First measurement of J/psi decay branching fractions into 2(pi+pi-)eta and 3(pi+pi-)eta channels with precise values.

Findings

Branching fraction for J/psi-->2(pi+pi-)eta: (2.26+-0.08+-0.27)×10^{-3}

Branching fraction for J/psi-->3(pi+pi-)eta: (7.24+-0.96+-1.11)×10^{-4}

First experimental determination of these decay modes.

Abstract

Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and (7.24+-0.96+-1.11)X10^{-4}, respectively.