CP asymmetries in neutralino production in e+e- collisions

Abstract

We study two CP sensitive triple-product asymmetries for neutralino production e+e- \to\tildeχ^0_i \tildeχ^0_j and the subsequent leptonic two-body decay \tildeχ^0_i \to \tilde l l, \tilde l \to \tildeχ^0_1 l, for ł= e,μ,τ. We calculate the asymmetries, cross sections and branching ratios in the Minimal Supersymmetric Standard Model with complex parameters μand M_1. We present numerical results for the asymmetries to be expected at a linear electron-positron collider in the 500 GeV range. The asymmetries can go up to 25 %. We estimate the event rates which are necessary to observe the asymmetries. Polarized electron and positron beams can significantly enhance the asymmetries and cross sections. In addition, we show how the two decay leptons can be distinguished by making use of their energy distributions.