1992/12/10 by Pankaj Jain, Jain, Pankaj, John P. Ralston +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9212243
To appear in Proceedings of DPF '92: Meeting of the American Physical Society (Fermilab 1992) (World Scientific, in press), 3 pages
arxiv created 1992/12/10 · arxiv updated 2009/11/30
Orbital angular momentum is crucial for the description of several process at large momentum transfer in the impulse approximation in perturbative QCD. We review the mechanism of independent scattering which makes violation of the helicity conservation rule possible at leading order - and without any need to flip a quark helicity - in exclusive hadron-hadron reactions. We argue that helicity flip form factors, which violate the factorization assumptions of conventional approaches and are classified as ``higher-twist," are nevertheless calculable to leading order in perturbative QCD when information on non-zero orbital angular momentum is incorporated.