Distinguishing new physics scenarios with polarized electron and   positron beams
  Contactlike nonstandard interactions can be revealed only through deviations of observables from the standard model predictions. We consider a number of such nonstandard scenarios, and discuss their identification as sources of deviations in fermion-pair production processes at the International Linear Collider, if they were observed. We emphasize the role of e^- and e^+ polarization in enhancing the identification reaches. 
A.A. Pankov, N. Paver and A.V. Tsytrinov