arXiv:hep-ph/0411112·v2·High Energy Physics — Phenomenology
The Longitudinal Structure Function at the Third Order
S. Moch (DESY, Zeuthen)🇩🇪 · J.A.M. Vermaseren (NIKHEF, Amsterdam)🇳🇱 · A. Vogt (Durham Univ., IPPP)🇳🇱
Abstract
We compute the complete third-order contributions to the coefficient functions for the longitudinal structure function F_L, thus completing the next-to-next-to-leading order (NNLO) description of unpolarized electromagnetic deep-inelastic scattering in massless perturbative QCD. Our exact results agree with determinations of low even-integer Mellin moments and of the leading small-x terms in the flavour-singlet sector. In this letter we present compact and accurate parametrizations of the results and illustrate the numerical impact of the NNLO corrections.
Comments: 11 pages, LaTeX, 4 eps-figures. DESY preprint number corrected