Direct, Resonant Production of States with Positive Charge Conjugation in Electron-Positron Annihilation.

Recent theory results on direct production of resonances with positive charge conjugationin electron-positron annihilation are reviewed. The strong modeldependence is emphasized, with predictions varying between 0.03 eV and 0.43 eV for the charmonium state with JPC = 1++ and between0.16 eV and4.25 eV for the state with JPC =2++. For the state with JPC = 0++ the cross section is of O ( m e 2 / M x 2) $ \left({\mathop m\nolimits_e^2 /\mathop M\nolimits_x^2 } \right) $ and thus negligeable for all practical purpose. The importance of the relative phase of the production amplitude is emphasized. [ABSTRACT FROM AUTHOR]