On Fermion Zero-Modes in Instanton V−AV-A Models With Spontaneous Symmetry Breaking

The left and right handed fermion zero-modes are examined. Their behaviour under the variation of the size of the instanton, \ri, and the size of the Higgs core, \rh, for a range of Yukawa couplings corresponding to the fermion masses in the electroweak theory are studied. It is shown that the characteristic radii of the zero-modes, in particlar those the left handed fermions, are locked to the instanton size, and are not affected by the variation of \rh, except for fermion masses much larger than those in the standard electroweak theory.Comment: 8 Pages. LaTeX file. 4 Figures Not include

Gaugino Condensation, Loop Corrections, and S-duality Constraint

This talk is a brief review of gaugino condensation in superstring effective field theories and some related issues (such as renormalization of the gauge coupling in the effective supergravity theories and modular anomaly cancellation). As a specific example, we discuss a model containing perturbative (1-loop) corrections to the K\"ahler potential and approximate S-duality symmetry.Comment: 11 pages, LaTeX, One figure included; To appear in the proceedings of NATO ASI on Masses of Fundamental Particles, C\`argese, France, Aug. 5-17, 199

Complex Monopoles in the Georgi-Glashow-Chern-Simons Model

We investigate the three dimensional Georgi-Glashow model with a Chern-Simons term. We find that there exist complex monopole solutions of finite action. They dominate the path integral and disorder the Higgs vacuum, but electric charges are not confined. Subtleties in the gauge fixing procedure in the path integral and issues related to Gribov copies are noted.Comment: 24 pages and 3 figures, Section 5 is extended,References adde

Gaugino Condensation with S-Duality and Field-Theoretical Threshold Corrections

We study gaugino condensation in the presence of an intermediate mass scale in the hidden sector. S-duality is imposed as an approximate symmetry of the effective supergravity theory. Furthermore, we include in the K\"ahler potential the renormalization of the gauge coupling and the one-loop threshold corrections at the intermediate scale. It is shown that confinement is indeed achieved. Furthermore, a new running behaviour of the dilaton arises which we attribute to S-duality. We also discuss the effects of the intermediate scale, and possible phenomenological implications of this model.Comment: 19 pages, LaTeX, 3 postscript figures include

Complex Monopoles in YM + Chern-Simons Theory in 3 Dimensions

In this talk, we give a brief discussion of complex monopole solutions in the three dimensional Georgi-Glashow model with a ChernSimons term. We find that there exist complex monopole solutions of finite action. They dominate the path integral and disorder the Higgs vacuum, but electric charges are not confined. Subtleties in the model and issues related to Gribov copies are also noted. 1. Introduction Monopole solutions can exist in gauge theories in which there is an unbroken compact U(1)group. The three dimensional SO(3) Yang-Mills theory with an adjoint Higgs field which breaks the SO(3) to U(1) (also known as the Georgi-Glashow model) was shown by Polyakov [1] to have monopole solutions which lead to the linear confinement of electric charges. The monopole contribution causes the Higgs vacuum to be `disordered', i.e., hh a i = 0 while hh a h a i = v 2 6= 0: In other words, long-range order in the Higgs vacuum is destroyed by the existence of monopoles. If now one adds the ..