A phenomenological study of the final combined HERA data on inclusive deep inelastic scattering has been performed. The data are presented and investigated for a kinematic range extending from values of the four-momentum transfer, $Q^2$, above $10^4{\mathrm{GeV}}^2$ down to the lowest values observable at HERA of $Q^2=0.045{\mathrm{GeV}}^2$ and Bjorken $x$, $x_{\text{Bj}}=6\times {10}^{-7}$. The data are well described by fits based on perturbative quantum chromodynamics (QCD) using collinear factorisation and evolution of the parton densities encompassed in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi formalism from the highest $Q^2$ down to $Q^2$ of a few ${\mathrm{GeV}}^2$. The Regge formalism with the soft Pomeron pole can describe the data up to $Q^2\approx 0.65{\mathrm{GeV}}^2$. The complete data set can be described by a new fit using the Abramowicz-Levin-Levy-Maor parametrization. The region between the Regge and the perturbative QCD regimes is of particular interest.

• Received 11 April 2017

DOI:https://doi.org/10.1103/PhysRevD.96.014001