Generalized double-logarithmic large-x resummation in inclusive deep-inelastic scattering

We present all-order results for the highest three large-x logarithms of the splitting functions Pqg and Pgq and of the coefficient functions Cϕ,q, C2,q and CL,g for structure functions in Higgs-and gauge-boson exchange DIS in massless perturbative QCD. The corresponding coefficients have been derived by studying the unfactorized partonic structure functions in dimensional regularization independently in terms of their iterative structure and in terms of the constraints imposed by the functional forms of the real-and virtual-emission contributions together with their Kinoshita-Lee-Nauenberg cancellations required by the mass-factorization theorem. The numerical resummation corrections are small for the splitting functions, but partly very large for the coefficient functions. The highest two (three for CL,g) logarithms can be resummed in a closed form in terms of new special functions recently introduced in the context of the resummation of the leading logarithms.