Gordon Cates
Neutron structure studies at medium and low energies using polarization degrees of freedom
The use of polarization degrees of freedom have played a key role in better understanding the structure of the nucleon. Examples include spin-structure studies using polarized deep  inelastic scattering as well as double-polarization techniques for studying the elastic nucleon  form factors. At lower energies, important quantities for characterizing the nucleon include the spin-independent and spin-dependent polarizabilities.  At present, there is a dearth of data on the forward spin-polarizabilities.  My talk will focus on features of nucleon structure that have been made possible through the use of large high-pressure polarized He-3 targets. Among the subjects  I will discuss is the extraction of flavor-separated nucleon form factors corresponding to elastic  scattering at high momentum transfer. Distinctly different behavior is evident for the u- and d-quark  contributions to the form factors,  a phenomenon that some have interpreted as evidence for the  importance of diquark correlations. I will also discuss the prospects of developing a scintillating  polarized He-3 target for use at HIGS. Such a target would be a major step toward measuring the nucleon spin-polarizabilities, as well as being useful in a variety of other experiments, including  measurements related to the GDH sum rule.