Abstract
In this paper we address various issues connected with transverse spin in light front QCD. The transverse spin operators, in the gauge, expressed in terms of the dynamical variables are explicitly interaction dependent unlike the helicity operator which is interaction independent in the topologically trivial sector of light-front QCD. Although it cannot be separated into an orbital and a spin part, we have shown that there exists an interesting decomposition of the transverse spin operator. We discuss the physical relevance of such a decomposition. We perform a one loop renormalization of the full transverse spin operator in light-front Hamiltonian perturbation theory for a dressed quark state. We explicitly show that all the terms dependent on the center of mass momenta get canceled in the matrix element. The entire nonvanishing contribution comes from the fermion intrinsiclike part of the transverse spin operator as a result of cancellation between the gluonic intrinsiclike and the orbital-like part of the transverse spin operator. We compare and contrast the calculations of transverse spin and helicity of a dressed quark in perturbation theory.
- Received 27 April 2000
DOI:https://doi.org/10.1103/PhysRevD.63.045006
©2001 American Physical Society