Quantum revivals and carpets in some exactly solvable systems

We consider the revival properties of quantum systems with an eigenspectrum E_{n} proportional to n^{2}, and compare them with the simplest member of this class - the infinite square well. In addition to having perfect revivals at integer multiples of the revival time t_{R}, these systems all enjoy perfect fractional revivals at quarterly intervals of t_{R}. A closer examination of the quantum evolution is performed for the Poeschel-Teller and Rosen-Morse potentials, and comparison is made with the infinite square well using quantum carpets.Comment: 5 pages, 5 figures (1 new), minor additions, to appear in J. Phys.

Precision Tests of Electroweak Physics

We review the current status of precision electroweak measurements and the constraints they impose on new physics. We perform a model independent analysis using the STU-formalism of Ref. 1, and then discuss how the Z-pole data from LEP and SLD can be used to constrain models that are not covered within that framework.Comment: 1 cover page + 8 pages, 8 postscript figures, LaTeX2e, ws-p9-75x6-50.cls, Talk presented at Hadron 13, Mumbai, India, January 14-20, 199

Improved lattice measurement of the critical coupling in phi(4)(2) theory

We use Monte Carlo simulations to obtain an improved lattice measurement of the critical coupling constant [lambda / mu^2]_crit for the continuum (1 + 1)-dimensional (lambda / 4) phi^4 theory. We find that the critical coupling constant depends logarithmically on the lattice coupling, resulting in a continuum value of [lambda / mu^2]_crit = 10.8(1), in considerable disagreement with the previously reported [lambda / mu^2]_crit = 10.26(8). Although this logarithmic behavior was not observed in earlier lattice studies, it is consistent with them, and expected analytically.Comment: 14 pages, 5 figure

Higgs boson interactions in supersymmetric theories with large tan beta

We show that radiative corrections to the Higgs potential in supersymmetric theories with large tan beta generically lead to large differences in the light Higgs boson decay branching fractions compared to those of the standard model Higgs boson. In contrast, the light Higgs boson production rates are largely unaffected. We identify W h associated production followed by Higgs boson decays to photons or to leptons via W W* as potential experimental probes of these theories.Comment: 11 pages, 4 figure

Charge assignments in multiple-U(1) gauge theories

We discuss the choice of gauge field basis in multiple-U(1) gauge theories. We find that there is a preferred basis, specified by the charge orthogonality condition, in which the U(1) gauge fields do not mix under one-loop renormalization group running.Comment: 7 pages, LaTe