2024/08/13 by BESIII Collaboration, Ablikim, M., Achasov, M. N. +649
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2408.06677
Using (2712± 14) × 106 ψ(2S) events collected with the BESIII detector at the BEPCII collider, we search for the decays ηc(2S)→ωω and ηc(2S)→ωϕ via the process ψ(2S)→γηc(2S). Evidence of ηc(2S)→ωω is found with a statistical significance of 3.2σ. The branching fraction is measured to be B(ηc(2S)→ωω)=(5.65±3.77(\rm stat.)±5.32(\rm syst.))×10-4. No statistically significant signal is observed for the decay ηc(2S)→ωϕ. The upper limit of the branching fraction at the 90% confidence level is determined to be B(ψ(2S)→γηc(2S),ηc(2S)→ωϕ)<2.24× 10-7. We also update the branching fractions of χcJ→ ωω and χcJ→ωϕ decays via the ψ(2S)→γχcJ transition. The branching fractions are determined to be B(χc0→ωω)=(10.63±0.11±0.46)× 10-4, B(χc1→ωω)=(6.39±0.07±0.29)× 10-4, B(χc2→ωω)=(8.50±0.08±0.38)× 10-4, B(χc0→ωϕ)=(1.18±0.03±0.05)× 10-4, B(χc1→ωϕ)=(2.03±0.15±0.12)× 10-5, and B(χc2→ωϕ)=(9.37±1.07±0.59)× 10-6, where the first uncertainties are statistical and the second are systematic.