Strong Interaction Effects in Scalar Top Production

We discuss effects of fragmentation and hard gluon radiation on the signal for the pair production of the lighter scalar top eigenstate $\tilde{t}_1$ at e^+e^- colliders. The main emphasis is on scenarios with small stop--LSP mass splitting, where strong interaction effects can considerably modify kinematical properties of the final state.Comment: 4 pages, 2 figures, uses sprocl.sty. Proceedings of the LCWS99, International Workshop on Linear Colliders, Sitges, Spain (May 1999) and Particles in Astrophysics and Cosmology: From Theory to Observation, Valencia, Spain (May 1999

Determination of Leptoquark Properties in Polarized eγe\gamma Collisions

We study leptoquark production using polarized $e\gamma$ colliders for the center of mass energies $\sqrt s=500$~GeV and 1~TeV. We show that using polarization asymmetries the ten different types of leptoquarks listed by Buchm\"uller, R\"uckl and Wyler can be distinquished from one another for leptoquark masses essentially up to the kinematic limit of the respective colliders. Thus, if a leptoquark were discovered an $e\gamma$ collider could play a crucial role in determining its origins.Comment: 10 pages (plus 10 postscript figures submitted separately), OCIP/C 94-

Resolved Photon Contributions to Leptoquark Production in e+e−e^+ e^- and eγe\gamma Collision

We calculate the resolved photon contribution to leptoquark production at $e\gamma$ colliders for the center of mass energies $\sqrt s=500$~GeV and 1~TeV. We also calculate the resolved photon contribution to leptoquark production at $e^+ e^-$ colliders for the center of mass energies $\sqrt{s} = 1$~and~2~TeV. In both cases we find that these contributions are considerably larger than the standard contributions considered in the literature.Comment: 9 pages (5 postscript figures in separate uuencoded file), OCIP/C 93-1