Spin Effects in Large Transverse Momentum Exclusive Scattering Processes

Nucleon-nucleon scattering at large momentum transfer is analyzed within the framework of quantum chromodynamic quark and gluon interactions. The spin dependence of the hadronic amplitude is found to be particularly sensitive to the underlying dynamical mechanisms. Detailed discussions of the quark interchange and Landshoff pinch singularity contributions are given for large angle pp, np and pi; elastic scattering. A possible explanation is given for the large spin-spin correlations measured by Crabb et al. We also define a new SU(2) symmetry group, -H-spin, which generalizes conventional helicity, and is an exact symmetry of the quark interchange process.