Fermi Motion and Quark Off-Shellness in Elastic Vector-Meson Production

Abstract

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 of the longitudinal cross section to the transverse one. 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 1/Q^8. 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 rho' and the psi'.

23 pages, LaTeX, 14 figures. Some equations have been corrected, and the figures are updated to include the latest published data from ZEUS. Following the injunction of the chairman of the H1 collaboration, we have removed all H1 public preliminary data from our comparative plots

References in corpus (4)

• The Effect of Higher Order Corrections to the BFKL Equation on the Perturbative Pomeron
• Proton Dissociative Rho and Elastic Phi Electroproduction at HERA
• Photo-production of psi' Mesons at HERA
• Gauge Invariance and Factorisation in Exclusive Meson Production

Cited by in corpus (12)

• Diffractive Electroproduction of rho and phi Mesons at HERA
• Q^2 dependence of diffractive vector meson electroproduction
• Spin Density Matrix Elements in Exclusive rho^0 Electroproduction on 1H and 2H Targets at 27.5 GeV Beam Energy
• New anomalous trajectory in Regge theory
• A measurement of the t dependence of the helicity structure of diffractive rho meson electroproduction at HERA
• DIS structure functions and the double-spin asymmetry in ${\rho }^0$ electroproduction within a Regge approach
• A Unified Model of Exclusive ${\rho }^0$, $\varphi$ and $\jpsi$ Electroproduction
• Electroproduction of vector mesons - factorization of end-point contributions
• Helicity in diffractive vector-meson production
• Diffractive $\varphi$ Production in a Perturbative QCD Model
• The Pomeron in Exclusive $J/\psi$ Vector Meson Production
• Hard Diffraction in Vector Meson Production at HERA