Spin effects in high-energy proton-proton scattering within a diquark   model
  We study $pp$ scattering at high energies and moderately large momentum transfer, using a model in which the proton is viewed as being composed of a quark and a diquark. We show that this model leads to single and double spin transverse asymmetries which are neither small nor vanish at high energies. 
S.V.Goloskokov and P. Kroll