Infrared Renormalons and Power Corrections in Deep-Inelastic Sum Rules

Infrared renormalons and $1\mathrm{/}{Q}^2$ power corrections in deep-inelastic sum rules are studied. The renormalization of operators with power divergence are discussed. The higher-twist terms in the operator product expansion are shown to account for the residual soft contributions survived from the Kinoshita-Lee-Nauenberg type of cancellation in Feynman diagrams. The presence of some degree of arbitrariness in the twist separation allows one to define the most convenient higher-twist operators suitable for a particular non-perturbative method. The discussion is focused on the Bjorken sum rule, for which the $1\mathrm{/}{Q}^2$ corrections are considered on a lattice.