Strong-interaction effects in stop pair production
at e+ e- colliders
M. Drees1 - O.J.P. Éboli1,2
1 Instituto de Física Teórica , Universidade Estadual
Rua Pamplona 145, São Paulo, SP 01405-900, Brazil
2 Department of Physics, University of Wisconsin, Madison, WI 53706, USA
Received: 19 February 1999 / Revised version: 12 March 1999 / Published online: 3 August 1999
We discuss perturbative and non-perturbative strong-interaction effects in the pair production of stop squarks () at e+ e- colliders. Events with an additional hard gluon allow to detect or exclude production even in scenarios with very small mass splitting between and an invisible lightest supersymmetric particle (LSP). Such events can also help to establish that transforms as a triplet under SU(3).We also carefully study non-perturbative fragmentation, which is currently not well understood: not only is the fragmentation function not known very well, but also there are ambiguities in the algorithm employed to model fragmentation. We present numerical results both for CERN LEP-183 and for a proposed future e+ e- collider operating at center-of-mass energy s1/2=500GeV.