Abstract:
In the integer-charge quark model, it is found that because of the photon-gluon mixing, only the zero-helicity gluons couple to deep-inelastic probes. As a particular consequences, gluons do not contribute to the (longitudinal) polarization asymmetry σ (↑↓) − σ (↑↑) in polarized electroproduction in the scaling limit. © 1980, All rights reserved.