Nonuniversal GUT corrections to the soft terms and their implications in supergravity models

Potentially large non-universal corrections to the soft supersymmetry\nbreaking parameters arise from their evolution between the Planck and the\ngrand-unification scales. We detail typical patterns of non-universality in GUT\nmodels, as well as elaborate on their propagation to the weak scale and on\ntheir low-energy implications. Possible corrections to the different scalar\nquark and lepton masses and the Higgs and the gaugino-Higgsino sector\nparameters are described in detail, and new allowed regions of the parameter\nspace are pointed out. In particular, the patterns studied often lead to\nheavier Higgsinos and $t$-scalar. One-loop GUT threshold corrections to the\nsoft parameters are also discussed and shown to be important.\n