Eur. Phys. J. C 24, 297-310 (2002)
DOI: 10.1007/s100520200945

Selectron pair production at e^-e^- and e⁺e^- colliders with polarized beams

C. Blöchinger¹, H. Fraas¹, G. Moortgat-Pick² and W. Porod<sup>3, 4

1</sup>  Institut für Theoretische Physik und Astrophysik, Universität Würzburg, 97074 Würzburg, Germany
²  DESY, Deutsches Elektronen-Synchrotron, 22603 Hamburg, Germany
³  Institut für Hochenergiephysik, Öster. Akademie d. Wissenschaften, 1050 Vienna, Austria
⁴  Institut für Theoretische Physik, Universität Zürich, 8057 Zürich, Switzerland

(Received: 30 January 2002 / Published online: 8 May 2002 - © Springer-Verlag / Società Italiana di Fisica 2002 )

Abstract
We investigate selectron pair production and decay in e^-e^- scattering and e⁺e^- annihilation with polarized beams taking into account neutralino mixing as well as initial state radiation and beamstrahlung corrections. One of the main advantages of having both modes at disposal is their complementarity concerning the threshold behavior of selectron pair production. In e^-e^- the cross sections at threshold for and increase proportional to the momentum of the selectron and in e⁺ e^- that for . Measurements at threshold with polarized beams can be used to determine the selectron masses precisely. Moreover we discuss how polarized electron and positron beams can be used to establish directly the weak quantum numbers of the selectrons. We also use selectron pair production to determine the gaugino mass parameter M₁. This is of particular interest for scenarios with non-universal gaugino masses at a high scale resulting in at the electroweak scale. Moreover, we consider also the case of non-vanishing selectron mixing and demonstrate that it leads to a significant change in the phenomenology of selectrons.

© Società Italiana di Fisica, Springer-Verlag 2002