arXiv:1110.6516·v3·High Energy Physics — Phenomenology
On gauge invariant nucleon spin decomposition
P. M. Zhang🇨🇳 · D. G. Pak🇨🇳
Abstract
A non-uniqueness problem of gauge invariant separation of quark and gluon contributions to nucleon spin is considered. We show that there is a wide number of gauge invariant spin decompositions each of them reduces to the canonical one in a special gauge. A class of physical gauge equivalent nucleon spin decompositions is selected by requirements of consistence with helicity notion described within E(2) little group representation theory and with gluon helicity \Delta g measured in experiment.
Comments: 5 pages, final version accepted by EPJA