Search

In rigid supersymmetry, generic models of dynamical supersymmetry breaking contain a light Goldstone boson, called the R axion. We show that supergravity effects explicitly break the R symmetry and give mass to the R axion. For visible and renormalizable hidden sector models, the massive R axion is free from astrophysical and cosmological problems. For nonrenormalizable hidden sector models, the R axion suffers from cosmological difficulties similar to those of the moduli fields in string theory., Comment: Talk given at 18th Johns Hopkins Workshop, Florence, Italy.

We compute the full set of weak-scale gauge and Yukawa threshold corrections in the minimal supersymmetric standard model, including all finite (non-logarithmic) corrections, which we show to be important. We use our results to examine the effects of unification-scale threshold corrections in the minimal and missing-doublet SU(5) models. We work in the context of a unified mass spectrum, with scalar mass M_0 and gaugino mass M_1/2, and find that in minimal SU(5) with squark masses less than one TeV, successful gauge and Yukawa coupling unification requires M_1/2 << M_0 and M_0 \simeq 1 TeV. In contrast, we find that the missing-doublet model permits gauge and Yukawa unification for a wide range of supersymmetric masses., Comment: 11 pages, 6 figures included, uses epsf.tex

All generic, calculable models of dynamical supersymmetry breaking have a spontaneously broken $R$ symmetry and therefore contain an $R$ axion. We show that the axion is massive in any model in which the cosmological constant is fine-tuned to zero through an explicit $R$-symmetry-breaking constant. In visible-sector models, the axion mass is in the 100 MeV range and thus evades astrophysical bounds. In nonrenormalizable hidden-sector models, the mass is of order of the weak scale and can have dangerous cosmological consequences similar to those already present from other fields. In renormalizable hidden- sector models, the axion mass is generally quite large, of order $10^7$ GeV. Typically, these axions are cosmologically safe. However, if the dominant decay mode is to gravitinos, the potentially large gravitino abundance that arises from axion decay after inflation might affect the successful predictions of big-bang nucleosynthesis. We show that the upper bound on the reheat temperature after standard inflation can be competitive with or stronger than bounds from thermal gravitino production, depending on the model and the gravitino mass., Comment: Minor changes to bring the archived version of the paper into alignment with the published version

Invited talk presented at the Workshop on Physics at Current Accelerators and the Supercollider, Argonne, Illinois, and at the 17th Johns Hopkins Workshop on Current Problems in Particle Theory, Budapest, Hungary., Comment: JHU-TIPAC-93022. Five embedded eps figures, submitted as a uuencoded file

Nonrenormalizable couplings in supergravity-coupled supersymmetric theories can give rise to power-law divergences that destabilize the weak-scale hierarchy. For the case of the standard-model gauge group, the problem can arise in theories with \321 gauge-singlet chiral superfields. The minimal supersymmetric standard model is free from such destabilizing divergences., Comment: JHU-TIPAC-93018

In this talk we survey the SSC and LHC signals and backgrounds for the physics of electroweak symmetry breaking. We study the process $pp \rightarrow WWX$ and compute the rate for the ``gold-plated'' signals $W^\pm \rightarrow \ell^\pm \nu$ and $Z \rightarrow \ell^+\ell^-$ $(\ell = e,\mu)$ for a wide variety of models. We use a forward jet tag and central jet veto to suppress the standard-model backgrounds. In this way we estimate the SSC and LHC sensitivities to the physics of electroweak symmetry breaking., Comment: JHU-TIPAC-920029, Presented at the 1992 Meeting of the DPF, Fermilab

In this talk we survey the SSC signals and backgrounds for the physics of electroweak symmetry breaking. We study the process $pp \rightarrow WWX$ and compute the rate for the ``gold-plated'' signals $W^\pm \rightarrow \ell^\pm \nu$ and $Z \rightarrow \ell^+\ell^-$ $(\ell = e,\mu)$ for a wide variety of models. We use a forward jet tag and central jet veto to suppress the standard-model backgrounds. In this way we estimate the SSC sensitivity to the physics of electroweak symmetry breaking. (Revised version contains style file ichep.sty.), Comment: 5 pages; JHU-TIPAC-920028; Talk given at the XXVI ICHEP, Dallas

Nontopological solitons, or ``bags,'' can arise when fermions acquire their mass through a Yukawa coupling to some scalar field. Bags have played an important role in models of baryons, nuclei, and more recently, in the idea that a Higgs condensate may form around a very heavy top quark. It has been claimed that deep bags, which correspond to tightly-bound states of fermions, will form when the Yukawa coupling is strong. Quantum corrections, however, are significant in this regime. We examine the effects of these quantum corrections on the formation of nontopological solitons in an exactly solvable large-$N$ model. We find that quantum bags differ dramatically from those of the classical theory. In particular, for large Yukawa coupling, the bags remain shallow and the fermions weakly bound., Comment: Talk given at the XXVI Int. Conf. on High Energy Physics, August, 1992 LATEX file, 7 pages + 2 figures available upon request, JHU-TIPAC-920021