Study of e plus e-→ σ0σ over bar 0 and σ plus σ over bar - by initial state radiation method at Belle
2023
Abstract
The processes e thorn e- -> sigma 0 sigma over bar 0 and e thorn e- -> sigma thorn sigma over bar - 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 thorn e- collider. The cross sections from the mass threshold to 3 GeV=c2 and the effective form factors of sigma 0 and sigma thorn are measured.
In the charmonium region, we observe the decays J=yr -> sigma 0 sigma over bar 0 and J=yr -> sigma thorn sigma over bar - and determine the respective branching fractions.