Fermi notion and quark off-shellness in elastic vector-meson production Original Research Article

We study ways of implementing Fermi momentum in elastic vector-meson production, and find that the usual on-shell assumption of quark models and quark wave functions cannot reproduce the ratio σL/σT. We propose a new approach which allows the quarks to be off-shell, and which naturally reproduces the data. As a consequence, we prove that the asymptotic form of the transverse cross section is different from σT ≈ 1/Q8. In this new model, we show that the mass, t and Q2 dependence of the cross sections are also reproduced. We also make predictions concerning the production of excited states such as the ϱ′ and the ψ′.