Higgsinos in SUSY models with gaugino mass unification

In the MSSM, the assumptions of a common sfermion mass parameter m0 and a common gaugino mass parameter m1/2, along with the requirements from radiative electroweak symmetry breaking, lead to relatively large values of the Higgs mixing parameter μ, and consequently to a gaugino-like lightest neutralino χ̃10. Lifting the requirement that the Higgs mass parameters mHD and mHU unify with the sfermion masses is known to allow for smaller μ. We show that a μ parameter sufficiently small to yield a Higgsino-like neutralino χ̃10 requires a precise adjustment of the Higgs mass parameter mHU. Consequently a gaugino-type neutralino is still preferred in SUSY models with gaugino mass unification.