Twist three distribution e(x): Sum rules and equation of motion relations

We investigate the twist three distribution function e(x) in light-front Hamiltonian perturbation theory. In light-front gauge, by eliminating the constrained field, we find a mass term, an intrinsic transverse momentum dependent term and a 'genuine twist three' quark-gluon interaction term in the operator. The equation of motion relation, moment relation and the sum rules are satisfied for a quark at one loop. We compare the results with other model calculations. (C) 2010 Elsevier B.V. All rights reserved.