is caused by the presence of the Sudakov form factors. A distinct behavior between the photoproduction results and those of direct $pp$ collision is present in virtue of the different approaches implemented in both cases. In the direct $pp$ collision approach, there are two distribution functions expressing the content of the two interacting protons, while the photoproduction possesses only one distribution function. Thus, the behavior of the photoproduction results is expected not to fit like the results of direct $pp$ collisions. Analysing the dependence on the photon virtuality, one sees a fast decreasing of the event rate in the range below Q$^{2} \approx$ 0.2 GeV$^{2}$. In the extended range of photon virtuality, the behavior of the event rate is fitted up to Q$^{2}$ = 1.0 GeV$^{2}$, showing a fast decreasing to zero and a subsequent growth with distinct rates in each parametrization. This behavior on Q$^{2}$ occurs due to the special form of the function ${\cal{X}}(\boldsymbol{k}^{2},Q^{2})$, which diverges for Q$^{2} =$ 0.

Extending this numerical analysis, the event rate is predicted adopting some distribution functions for the gluon content in the proton. As explained in the Sec. III, the non-diagonality of the distributions was approximated by a multiplicative factor which 