ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2013, vol. 87, p. -
Observation of ηc decay into Σ+Σ ̄- and Ξ-Ξ̄ + final states
Using a data sample of 2.25×108 J/ψ events collected with the BESIII detector, we present the first observation of the decays of ηc mesons to Σ+Σ̄ - and Ξ-Ξ̄+. The branching fractions are measured to be (2.11±0.28stat± 0.18syst±0.50PDG)×10-3 and (0.89±0.16stat±0.08syst±0.21 PDG)×10-3 for ηc→Σ +Σ̄- and Ξ-Ξ ̄+, respectively. These branching fractions provide important information on the helicity selection rule in charmonium-decay processes. © 2013 American Physical Society.