Is nucleon spin structure inconsistent with the constituent quark model? art. no. 114032

Proton spin structure discovered in polarized deep inelastic scattering is shown to be consistent with the valence-sea quark mixing constituent quark model. The relativistic correction and quark-antiquark pair creation (annih ilation) terms inherently involved in the quark axial vector current suppre ss the quark spin contribution to the proton spin. The relativistic quark o rbital angular momentum provides compensative terms to keep the proton spin 1/2 untouched. The tensor charge of the proton is predicted to have a simi lar but smaller suppression. An explanation on why baryon magnetic moments can be parametrized by the naive quark model spin content as well as the sp in structure discovered in polarized deep inelastic scattering is given. [S 0556-2821(98)06421-2].