Chargino searches at LEP for complex MSSM parameters

Abstract

We reanalyze the results of the chargino searches at LEP (on the basis of the DELPHI 189 GeV data sample), including the possibility of complex MSSM parameters. We point out the possible differences between the complex- and real-parameter analysis. We check that the regions excluded by “standard” analyses remain generally robust against the introduction of complex parameters, with the exception of light sneutrino and low tan β scenario, where taking into account the full LEP luminosity or the additional constraints like those given by the Z 0 width or electric dipole moment measurements are necessary.