More on Large $Q^2$ Events with Polarized Beams
  We discuss polarized proton-positron scattering in the context of the excess of large $Q^2$ events at HERA. We define and estimate a polarized asymmetry to examine two scenarios, the contact interaction and the stop scenario with broken R-parity. This asymmetry exhibits a characteristic behavior depending on the scenarios. Thus the polarized experiment at HERA will provide with a good test for these models. 
J. Hashida and Y. Kiyo