Angular and Energy Distribution in Neutralino Production and Decay with complete Spin Correlations

Abstract

We study the process e^{-}e^{+} \to \tilde{\chi}^0_1\tilde{\chi}^0_2 with the subsequent decay \tilde{\chi}^0_2 \to \tilde{\chi}^0_1 \ell^{+}\ell^{-} taking into account the complete spin correlations between production and decay. We present numerical results for the lepton angular distribution and the distribution of the opening angle between the outgoing leptons for \sqrt{s}=182 GeV. We examine representative mixing scenarios in the MSSM and study the influence of the common scalar mass parameter m_0. For the lepton angular distribution the effect of the spin correlations amounts to up to 20%. The shape of the lepton angular distribution is very sensitive to the mixing in the gaugino sector and to the value of m_0. We find that the opening angle distribution is suitable for distinguishing between Higgsino-like and gaugino-like neutralinos.