2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197147An explicit analytic formula for the transverse and longitudinal impact factors S_{T,L}(N,γ) of the photon using k_T factorization with exact gluon kinematics is given. Applications to the QCD dipole model and the extraction of the unintegrated gluon structure function from data are proposed.latex file, 14 pages, no figure, Saclay,theory and Cracow,jagelonian U. preprintHigh Energy Physics - Phenomenologytext