Search for ηc(2S)hc→ pp¯ decays and measurements of the χcJ→ pp¯ branching fractions

Abstract

Using a sample of 1.06 × 108φ(3686) events collected with the BESIII detector at BEPCII, the decays ηc(2S) → pp¯ and hcpp¯ are searched for, where ηc(2S) and hc are reconstructed in the decay chains φ(3686) → γηc(2S), ηc(2S) → pp¯ and χ(3686) → π0hc, hc→ pp¯, respectively. No significant signals are observed. The upper limits of the product branching fractions are determined to be B(φ(3686) → γηc(2S)) × B(ηc(2S) → pp¯) < 1.4 × 10-6and B(φ(3686) → π0hc) × B(hc→ pp¯) < 1.3 × 10-7at the 90% C.L.. The branching fractions for χcJ→ pp¯ (J = 0, 1, 2) are also measured to be (24.5 ± 0.8 ± 1.3, 8.6 ± 0.5 ± 0.5, 8.4 ± 0.5 ± 0.5) × 10-5, which are the world's most precise measurements. © 2013 American Physical Society.