On possible resolution of spin crisis in the parton model

The recent EMC deep inelastic experiment using a polarized muon beam scattering on a polarized proton target has raised serious quastions about understanding of how the spin of the proton is related to that of its partonic constituents, resulting in what has been termed a spin crisis. Several attempts have been made to resolve the problem. It is shown that for the range of Q2 involved in the EMC experiment there exist large higher twist corrections linked to the Gerasimov, Drell, Hearn sum rule. Taking account of these effects helps, both in sign and magnitude, to resolve the problem