ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2011, vol. 83, p. -
Observation of χcJ decaying into the pp̄K +K- final state
First measurements of the decays of the three χcJ states to pp̄K+K- final states are presented. Intermediate η →K+K- and Λ(1520)→pK- resonance states are observed, and branching fractions for χ cJ→p̄K+Λ(1520), Λ(1520) Λ̄(1520), and η pp̄ are reported. We also measure branching fractions for direct χcJ→pp̄K+K- decays. These are first observations of χcJ decays to unstable baryon resonances and provide useful information about the χcJ states. The experiment uses samples of χcJ mesons produced via radiative transitions from 106×106 ψ′ mesons collected in the BESIII detector at the BEPCII e+e- collider. © 2011 American Physical Society.