Diffractive production of vector mesons in lepton-nucleon reactions

Abstract

We calculate cross sections for the production of vector mesons V in reactions if ℓ + N → ℓ' + V + N, ℓ, ℓ' = ν, e, μ, taking into account all presently known information from electroproduction of ϱ's. This leads to considerable differences in results from previous calculations, often more than an order of magnitude. The results for the ϱ are then largely a translation of electroproduction data into ν predictions and they will provide a direct test of the relation of weak and electromagnetic currents. The y or Q 2 distributions for the ϱ are instructive. The prediction for the A 1 provides a direct test of the existence of the A 1 and of whether vector and axial vector currents materialize into particles in the same way. The detection of a B meson would provide direct evidence for second-class currents and a measurement of their strength. We estimate all F ∗ production will account for at most 2% of the total ν cross section at FNAL energies, which must be multiplied by the muon semi-leptonic branching ratio (and possibly a factor of 2 for an axial vector F ∗) to calculate its contribution to the dimuon event rate.