Observation of OZI-suppressed decays $\chi_{cJ}\to\omega\phi$

Abstract

Decays χcJ (J=0,1,2)→ωϕ are studied using (448.1±2.9)×106 ψ(3686) events collected with the BESIII detector in 2009 and 2012. In addition to the previously established χc0→ωϕ, first observation of χc1→ωϕ is reported in this paper. The measured product branching fractions are B(ψ(3686)→γχc0)×B(χc0→ωϕ)=(13.83±0.70±1.01)×10−6 and B(ψ(3686)→γχc1)×B(χc1→ωϕ)=(2.67±0.31±0.27)×10−6, and the absolute branching fractions are B(χc0→ωϕ)=(13.84±0.70±1.08)×10−5 and B(χc1→ωϕ)=(2.80±0.32±0.30)×10−5. We also find a strong evidence for χc2→ωϕ with a statistical significance of 4.8σ, and the corresponding product and absolute branching fractions are measured to be B(ψ(3686)→γχc2)×B(χc2→ωϕ)=(0.91±0.23±0.12)×10−6 and B(χc2→ωϕ)=(1.00±0.25±0.14)×10−5. Here, the first errors are statistical and the second ones systematic.