arXiv:0910.2567·v1·High Energy Physics — Phenomenology
Lorentz invariance relations and Wandzura-Wilczek approximation
T. Teckentrup (Ruhr U., Bochum)🇩🇪 · A. Metz (Temple U.)🇺🇸 · P. Schweitzer (Connecticut U.)🇺🇸
Abstract
A complete list of the so-called Lorentz invariance relations between parton distribution functions is given and some of their consequences are discussed, such as the Burkhardt-Cottingham sum rule. The violation of these relations is considered in a model independent way. It is shown that several Lorentz invariance relations are not violated in a generalized Wandzura-Wilczek approximation, indicating that numerically their violation may be small.
Comments: 10 pages; Proceedings of the workshop "Recent Advances in Perturbative QCD and Hadronic Physics", July 20-24, 2009, at ECT*, Trento (Italy), in honor of Anatoli V. Efremov on the occasion of his 75th birthday; to appear in Mod. Phys. Lett. A