First measurements of χcJ → ς- ς ¯ + (J=0,1,2) decays FIRST MEASUREMENTS of ⋯ M. ABLIKIM et al.

Abstract

We measured the branching fractions of the decays χcJ→ς-ς¯+ for the first time using the final states nn¯π+π-. The data sample exploited here is 448.1×106 ψ(3686) events collected with BESIII. We find B(χcJ→ς-ς¯+)=(51.3±2.4±4.1)×10-5,(5.7±1.4±0.6)×10-5, and (4.4±1.7±0.5)×10-5, for J=0, 1, 2, respectively, where the first uncertainties are statistical and the second systematic.