Aspects of the phenomenology of string-inspired supergravity models.

摘要

In this dissertation we calculate the one loop quantum contributions to soft supersymmetry breaking terms in the scalar potential as well as gaugino masses in supergravity theories regulated a la Pauli-Villars. We find "universal" contributions, independent of the regulator masses and tree level soft supersymmetry breaking, that contribute gaugino masses and A-terms equal to the "anomaly mediated" contributions found in analyses using spurion techniques, as well as a scalar mass term not identified in those analyses. The universal terms are in general modified---and in some cases canceled---by model-dependent terms. We emphasize the model dependence of loop-induced soft terms in the potential, which are much more sensitive to the details of Planck scale physics then are the one loop contributions to gaugino masses.; Next, a systematic analysis of soft supersymmetry breaking terms at the one loop level is performed in a large class of string effective field theories. We show that the pattern of supersymmetry breaking depends on the detailed prescription of the regularization process which is assumed to represent the Planck scale physics of the underlying fundamental theory. The usual anomaly mediation case with vanishing scalar masses at one loop is not found to be generic. We also discuss the supersymmetric spectrum of O-I and O-II orbifold compactification models.; Finally, we study the phenomenology of a class of models describing modular invariant gaugino condensation in the hidden sector of a low energy effective theory derived from the heterotic string. Placing simple demands on the resulting observable sector, such as a supersymmetry breaking scale of approximately 1 TeV, a vacuum with properly broken electroweak symmetry, superpartner masses above current direct search limits, etc., results in significant restrictions on the possible configurations of the hidden sector. We include in this analysis an investigation of the dark matter prospects of supersymmetric models such as these with nonuniversal gaugino masses. The cosmologically viable regions of parameter space are investigated, allowing very specific statements to be made about the content of the supersymmetry breaking hidden sector