SO(10) Yukawa unification with μ<0

We consider the low energy implications including particle spectroscopy of SO(10) inspired t-b-τ Yukawa coupling unification with μ<0, where μ is the coefficient of the bilinear Higgs mixing term of the minimal supersymmetric standard model (MSSM). We employ non-universal MSSM gaugino masses induced by SO(10) invariant dimension five operators, such that the total number of fundamental parameters is precisely the same as in Yukawa unified supersymmetric SO(10) models with universal gaugino masses and μ>0. We find that t-b-τ Yukawa unification with μ<0 is compatible with the current experimental bounds, including the WMAP bound on neutralino dark matter and the measured value of the muon anomalous magnetic moment. We present a variety of benchmark points which include relatively light squarks (∼TeV) of the first two families and an example in which the bottom and top squarks are lighter than the gluino. This is quite distinct from Yukawa unification with μ>0 and universal gaugino masses in which the gluino is the lightest colored sparticle and the squarks of the first two families have masses in the multi-TeV range.