Vector-meson-proton cross-sections from deep-inelastic-scattering data

Contrary to naive scaling, vector-meson-proton total cross-sections are not proportional, at high collision energies, to the geometrical sizes of the vector mesons concerned. The ansatz (m2+M2)·σvp=const, whereM is the proton mass, is found to be sufficient to produce cross-section ratios\(\sigma _{\rho p} :\sigma _{\omega p} :\sigma _{\varphi p} :\sigma _{\psi p} = 7.1:7.1:5.5:1\) in agreement with experiment, if this were all one wanted. Actually the constant in this modified scaling law can be fixed by using the generalized vector-meson dominance model to relateσvp to the virtual Compton cross-section\(\sigma _{\gamma p} (\nu ,Q^2 )\)(ν Q2) and hence to the deep-inelastic-scattering data. Consequently,σvp can be determined in absolute value. There are important consistency conditions which this scheme has to and does effectively satisfy.