Non-planar structure of analytical QCD predictions for the Gottfried sum rule
Abstract
Description
It is stressed that within large N_c-expansion {\bf analytical calculations} of the $(α_s/π)^2$ QCD contributions to the valence part of the Gottfried sum rule for F_2 structure function of charged leptons-nucleon deep-inelastic scattering reveals the existence of the $O(1/N_c^2)$ {\bf non-planar} corrections only and the disappearance of the {\bf planar} O(N_c^0) perturbative terms. The relation between Gottfried and Adler sum rule for neutino-nucleon DIS is established and the proposal that the differebce between corresponding QCD corrections to higher non-singlet moments in charged-lepton and neutrino DIS are {\bf suppressed by 1/N_c^2} is made. The possible consequence of the cancellation of {\bf perturbative planar} graphs in the considered perturbative series, namely the existence of light-quark flavour asymmetry $\bar{u}(x)<\bar{d}(x)$, is mentioned. The effect of the similar origin, i.e. the relation of {\bf ``light-by-light-type''-type structure} in DIS characteristics at the $α_s^3$-level to the generation of light quark-antiquark asymmetry, is also commented.
12 pages, based on the talk at the Parralel Session of XI International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT07), April 23-27, 2007, Amsterdam; submitted to the Proceedings
12 pages, based on the talk at the Parralel Session of XI International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT07), April 23-27, 2007, Amsterdam; submitted to the Proceedings