5.5\mbox{ GeV}^{-2}$ [@miller]. This factor can be seen as the representation of the proton-Pomeron coupling. However, in order to assume the gluon ladder coupled to the proton, the consideration of zero momentum transfer in the proton vertex is not a sufficient condition. A small value for the momentum fraction is required in this region of interest, like $x = M_{H}/\sqrt{s} \sim 0.01$, such that one can safely put $t_{p} = 0$, and identify the distribution as the unintegrated gluon distribution function $f_{g}(x,\boldsymbol{k}^{2})$ evolved by the BFKL evolution equation [@KMR-1997].

Finally, the event rate has the form $$\begin{aligned}
\left. \frac{d\sigma}{dy_{H}d\boldsymbol{p}^{2}dt} \right|_{t,y_{H} = 0} = \frac{(1.2)^{2} }{162 \pi^{4} } \left( \frac{M^{2}_{H}}{N_{c}v} \right)^{2} \alpha_{s}^{4} \, \alpha^{2} \left( \sum_{q} e^{2}_{q} \right)^{2} e^{-B\boldsymbol{p}^{2}} \left[ \int  \frac{d\boldsymbol{k}^{2}}{\boldsymbol{k}^{6}} \; f_{g}(x,\boldsymbol{k}^{2}) \; {\cal{X}}(\boldsymbol{k}^{2},Q^{2}) \right]^{2}.
\label{dpH}\end{aligned}$$ For momentum conservation, there is a relation between the transversal components of the Higgs and the proton momenta, being $$\begin{aligned}
d\boldsymbol{p}^{2}_{H} \longrightarrow - \, d\boldsymbol{p}^{2}.
\label{dpH2}\end{aligned}$$ In Eq.(\[dpH\]), one can perform the last integration over the transversal component of the proton momentum, resulting in the final expression for the diffractive production in $\gamma p$ interaction $$\begin{aligned}
\left. \frac{d\sigma}{dy_{H}dt} \right|_{t,y_{H} = 0} = \frac{2 \alpha_{s}^{4} \, \alpha^{2} }{225 \pi^{4} \, b} \left( \frac{M^{2}_{H}}{N_{c}v} \right)^{2} 