Study of e + e - → Σ 0 Σ ¯ 0 and Σ + Σ ¯ - by initial state radiation method at Belle
The processes e + e - →Σ 0 $\overline{Σ}$ 0 and e + e - →Σ + $\overline{Σ}$ - are studied using initial-state-radiation events in a sample of 980 fb -1 collected with the Belle detector at the KEKB asymmetric-energy e + e - collider. The cross sections from the mass threshold to 3 GeV/c 2 and the effective form factors of Σ 0 and Σ + are measured. In the charmonium region, we observe the decays J/ψ →Σ 0 $\overline{Σ}$ 0 and J/ψ →Σ + $\overline{Σ}$ - and determine the respective branching fractions.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗