2025/06/10 by KEDR Collaboration, Anashin, V. V., Anchugov, O. V. +95
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.2506.08453
We present measurements of the branching fractions for the J/ψ meson decays into the ρη and ϕη final states, based on data collected with the KEDR detector at the VEPP-4M collider. The data set consisted of 4.93 million J/ψ events. The resulting branching fractions are: - B(J/ψ→ ρη) = (2.04 ± 0.58 ± 0.39)× 10-4, - B(J/ψ→ ϕη) = (7.82 ± 1.17 ± 0.58) × 10-4, where the first uncertainty is statistical and the second one is systematic. In the study of the ρη decay, the dynamics of J/ψ→π+π-η is analyzed. The hints from contributions of ρ(1450)η and a±2π∓ intermediate states are observed. Additional measured branching fractions in the model that includes ρ(1450)η and a±2π∓ are: - B(J/ψ→ π+π-η) = (4.73 ± 0.49 ± 1.17)×10-4, - B(J/ψ→ (a2+π- + a2- π+)) = (1.05± 0.37 ± 0.34)× 10-3, - B(J/ψ→ ρ(1450)η→ π+π-η) < 1.51 × 10-4, at a confidence level of 90%. All results are consistent with previous studies.