Final state interactions in the parton model and massive lepton pair production

A scheme of assignments for the 0⁺ nonet is proposed with the S¹ (1000) effect corresponding to resonance poles both on Sheet II and Sheet III, and with the ? located somewhere above 1100 MeV, e.g. at 1300 MeV. A tentative fit of the decay characteristics of these and the other nonet condidates, δ(970) and κ(～1200) is achieved with the mixing angle given by cos²θ_S～ 0.13 instead of the ‘ideal’ value of $\text{2}\text{3}$.