2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36986R measurement results in 2--5 GeV region by BESII is reported in this talk. The study on $σ$ particle in $J/ψ\to ωπ^+ π^-$, based on $7.8 \times 10^6$ BESI $J/ψ$ data, is also reported.4 pages, 7 figures, talk given at XXXVIth Rencontres De Moriond, QCD High Energy Hadronic Interactions, Les Arcs, Savoie, France, March 17-24, 2001High Energy Physics - Experimenttext