Search for hadronic transition χcJ→η cπ+π- and observation of χcJ→KK̄πππ

Abstract

Hadronic transitions of χcJ→ηcπ +π- (J=0, 1, 2) are searched for using a sample of 1.06×108 ψ(3686) events collected with the BESIII detector at the BEPCII storage ring. The ηc is reconstructed with KS0K ±π and K+K-π0 final states. No signals are observed in any of the three χcJ states in either ηc decay mode. At the 90% confidence level, the upper limits are determined to be B(χc0→ηcπ+π -)<0.07%, B(χc1→ηcπ +π-)<0.32%, and B(χc2→η cπ+π-)<0.54%. The upper limit of B(χc1→ηcπ+π-) is lower than the existing theoretical prediction by almost an order of magnitude. The branching fractions of χcJ→KS0K±π π+π-, K+K -π+π-π0, ωK+K -, and π+π-π0 J=0, 1, 2) are measured for the first time. © 2013 American Physical Society.