Regge residues from DGLAP evolution

Abstract

We show that combining forward and backward evolution allows to extract the residues of the triple-pole pomeron and of the other singularities for 10 GeV$^2 \le Q^2 \le 1000$ GeV$^2$. In this approach, the essential singularity generated by the DGLAP evolution is considered as a numerical approximation to a triple-pole pomeron. Using an analytical expression for the form factors, we reproduce the experimental data with a $χ^2/dof$ of 1.02. This proves the compatibility between Regge theory and DGLAP evolution. The method used here enables us to evaluate the uncertainties on the gluon distribution which prove to be large at small $x$ and small $Q^2$.