Spin Force Dependence Of Nucleon Structure Functions

Abstract

Deep inelastic structure functions for the nucleon are obtained in a constituent quark model on the light cone. In the Bjorken limit the parton model is derived. Structure functions from the hadronic tensor at the scale $\mu \sim 0.25$ GeV are evolved from (0.6 GeV$)^{2}$ to $-q^{2}\sim 15$ GeV$^{2}$. The model incorporates the quark boosts, is designed to describe form factors and structure functions, and to provide a link between the parton and constituent quark models. The main effect of the spin force between quarks is described in terms of smaller (and lighter) scalar $u-d$ quark pairs in the nucleon. To account for the negative slope of $F^{n}_{2}(x)/F^{p}_{2}(x)$, attraction between scalar $u-d$ quark pairs and incorporation of boosts are required. The two-body spin force between quarks from color magnetism also leads to a negative slope. The polarization asymmetry $A^{p}_{1}$ is in fair agreement with the EMC data in the valence quark region. Revised hep-ph/9401342, Phys. Rev. D.