Investigation into the limits of perturbation theory at low Q2 using HERA deep inelastic scattering data
AbstractA 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, Q2, above 104 GeV2 down to the lowest values observable at HERA of Q2=0.045 GeV2 and Bjorken x, xBj=6×10-7. 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 Q2 down to Q2 of a few GeV2. The Regge formalism with the soft Pomeron pole can describe the data up to Q2≈0.65 GeV2. 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.