Two-gluon form factor of the nucleon and J/ψ photoproduction

الأصل · EN

We argue that the t-dependence of the two-gluon form factor of the nucleon should be given by Γ(t)=(1-t/m₂g²)⁻² with m₂g²≈ 1 GeV². We demonstrate that this form provides a good description of the t-dependence of the cross section of the elastic photoproduction of J/ψ-mesons between the threshold region of Eγ=11 GeV (Cornell), Eγ=19 GeV (SLAC) and Eγ=100 GeV (FNAL) including the strong energy dependence of the t-slope. It is also well matched with the recent HERA data. The same assumption explains also the t-dependence of ϕ-meson electroproduction near threshold at W=2.3 GeV, Q²=1.0 GeV².