2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42388We study the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The contributions of twist-two and (renormalon-type) higher-twist operators of the Wilson operator product expansion are taken into account. The results are in good agreement with deep inelastic scattering experimental data from HERA.6 pages, 2 figures, latex. Talk presented at the XVI International Baldin Seminar on High Energy Physics Problems ``Relativistic Nuclear Physics and Quantum Chromodynamics'', Dubna, Russia, June 2002High Energy Physics - Phenomenologytext