Some Current Problems in Particle Physics Beyond the Standard Model
Abstract
In this thesis I address several problems in trying to extend particle physics beyond the standard model. In chapter 1, I compute the cross section for fermions scattering from cosmic string solitons which are left from symmetry breaking phase transitions in the early universe, and discuss the consequences for the possibility of observing the strings. In chapter 2, I derive the form of the WessZumino anomalous interaction term for the 2dimensional supersymmetric nonlinear sigmamodel; in chapter 3, a similar technique is applied to the 4dimensional supersymmetric nonlinear sigmamodel, and constraints are obtained on the form of lowenergy effective actions of supersymmetric gauge theories. In particular, it is shown that sigmamodels on compact manifolds cannot have a WessZumino interaction with unbroken supersymmetry. In chapter 4, I analyze a mechanism for breaking supersymmetry in supersymmetric string theories, which have the potential to provide unification of gauge interactions with gravity in a consistent quantum theory.
 Publication:

Ph.D. Thesis
 Pub Date:
 1985
 Bibcode:
 1985PhDT........46R
 Keywords:

 SUPERSTRINGS;
 SIGMA MODELS;
 COSMIC STRINGS;
 Physics: Elementary Particles and High Energy