The form factors ωπ0 and π+π- at ψ(2S)

摘要: The measurements of ψ (2 S )→ ωπ 0 and ψ (2 S )→ π + π − in e + e − experiments are examined. It is found that the non-resonance virtual photon annihilation gives large contributions to the observed cross sections of these two processes. By including this contribution, the form factors and branching fractions of these two decay modes are revised.