CP violation in selectron cascade decays [formula omitted

Abstract

Selectron decays constitute a source of 100% polarised neutralinos, whose helicity is fixed by the charge and “chirality” of the decaying selectron. In SUSY scenarios where the second neutralino χ˜20 has three-body decays, the cascade decay e˜L→eχ˜20→eχ˜10μ+μ− provides a clean place to study CP violation in the neutralino sector, through the analysis of CP-violating asymmetries involving the χ˜20 spin s→ and the momenta of the two muons. We show that a CP-violating asymmetry in the triple product s→⋅(p→μ−×p→μ+) could be observable at a 800 GeV linear collider provided the gaugino mass M1 has a large phase at the electroweak scale.