Neutralino Production and Decay at an ee Linear Collider with Transversely Polarized Beams

Once supersymmetric neutralinos χ̃0 are produced copiously at e+e− linear colliders, their characteristics can be measured with high precision. In particular, the fundamental parameters in the gaugino/higgsino sector of the minimal supersymmetric extension of the standard model (MSSM) can be analyzed. Here we focus on the determination of possible CP–odd phases of these parameters. To that end, we exploit the electron/positron beam polarization, including transverse polarization, as well as the spin/angular correlations of the neutralino production e+e− → χ̃i χ̃j and subsequent 2–body decays χ̃i → χ̃kh, χ̃kZ, l̃±Rl, using (partly) optimized CP– odd observables. If no final–state polarizations are measured, the Z and h modes are independent of the χ̃i polarization, but CP–odd observables constructed from the leptonic decay mode can help in reconstructing the neutralino sector of the CP–noninvariant MSSM. In this situation, transverse beam polarization does not seem to be particularly useful in probing explicit CP violation in the neutralino sector of the MSSM. This can most easily be accomplished using longitudinal beam polarization. Permanent Address Permanent Address