We examine classical vortex solutions of several relativistic planar field theories comprising an abelian gauge field minimally coupled to a Higgs field. We emphasize the properties of vortices arising in theories with a Chern-Simons term and briefly discuss their possible relevance to condensed matter physics. We conclude with a glimpse at how quantum analogues of these solutions might be obtained.

This talk will consider CP violating phases in supersymmetry models with a light mass spectrum. The framework of these models is supergravity grandunification. The problem is that these phases produce large electric dipole moments(EDM) of electron and neutron. One popular solution to this problem is the creation of cancellation among different diagrams which contribute to the EDM calculation. I will point out that this procedure requires fine tuning of parameters at the grand unification scale. I will talk about several scenarios where the EDM constraints can be naturally satisfied. Also, the predictions of these new scenarios in the ongoing and upcoming experiments will be discussed.

Experimental evidence that neutrinos have a tiny mass has grown in the late years. Since this is the first signal of physics beyond the Standard Model, one would like to know the energy scale at which this new physics resides. In this talk, I show how to derive model-independent upper bound on the scale of Majorana-neutrino mass generation. For neutrino masses implied by neutrino oscillation experiments, all but one of these bounds is less than the Planck scale, and they are all within a few orders of magnitude of the grand-unification scale.

The nature of confinement in QCD was recently included in a New York Times Science Section article (August 15) among a list of the "10 physics questions to ponder for a millenium or two." Model independent considerations lead to the notion of flux tubes as being responsible for confinement.

Excitation of the flux-tubes, which bind quarks in a meson, should lead to mesons with quantum numbers that are not possible with simple quark-antiquark systems. Mesons with exotic quantum numbers should be enhanced in photoproduction owing to the aligned spins of the virtual quark-antiquark in the beam. Yet we have essentially no data on the photoproduction of light quark mesons. This talk will describe a new project at Jefferson Lab to build a new facility which will use the energy-upgraded accelerator to search for these mesons using a beam of linearly polarized photons.

This Hall D project presentation will be made to the NSAC Long Range Planning Committee in Santa Fe on March 27, 2001 just prior to that committee's setting priorities for the next five years.

An overview of the physics and project was recently described in an article by Dzierba, Meyer and Swanson in the Sept/Oct 2000 issue of American Scientist and another by Dzierba and Isgur in the Sept 2000 issue of the CERN Courier. Weblinks to the articles and project site: http://www.sigmaxi.org/amsci/articles/00articles/dzierba.html http://www.cerncourier.com/main/article/40/7/16 http://dustbunny.physics.indiana.edu/HallD/

We discuss issues in an attempt to put the Standard Model (SM) in five-dimensional anti-de Sitter spacetime compactified on $S^1/Z_2$. The recently-proposed approach to the gauge hierarchy problem with the SM confined on a boundary, is extended to a situation where (some of) the SM particles reside in the five dimensional bulk. Unlike the compactification with the flat metric, these fermion zero modes couple to Kaluza-Klein (KK) excitations of the SM gauge bosons. Current electroweak precision data give a constraint that the first KK mode be heavier than 9 TeV. We also argue that at least the Higgs field should be confined on the brane to utilize the Randall-Sundrum backgroundas a solution to the gauge hierarchy. We also discuss about utilities of bulk fermions as a source of small neutrino masses and the fermion mass hierarchy.

Precision measurements involving low energy neutrons can be used to address a number of interesting physics issues. I will present a general summary of current and future research in this area. Among the subjects discussed will be: (1) measurements of the KM element Vud and the unitarity of the CKM matrix using neutron decay, (2) searches for non-standard model T violation, (3) the weak interaction between nucleons.

The new measurement of the anomalous magnetic moment of the muon, $a_mu=(g-2)/2$, for the positive muon at the Brookhaven Alternating Gradient Synchrotron will be presented and discussed. The result of this measurement is in good agreement with previous measurements and has a relative error of 1.3~parts-per-million, which is one third that of the combined previous data. The combined experimental value is 2\.6 standard deviations above the current theoretical value calculated within the Standard Model, which may be a hint for new physics.

Recommended reading: "Precise measurement of the positive muon anomalous magnetic moment", Phys. Rev. Lett. 86 (2001) 2227.

Additional information can be found on http://phyppro1.phy.bnl.gov/g2muon/

Measurements from deep-inelastic scattering of polarized leptons on polarized nucleon targets indicate that the valence quarks carry suprisingly little of the nucleon spin. They also indicate that the strange quark is responsible for -10% of the nucleon spin. Neutrino-nucleon elastic scattering can provide another test of this observation while avoiding many of the difficulties of the deep-inelastic measurements. The current status of neutrino-elastic scattering will be presented along with ideas about how to make a definitive measurement of the strange-spin of the nucleus in the near future.

There has been a large activity in the study of charmless B decays. Many of these modes have been observed recently by CLEO, and the B factories BABAR and BELLE. Needless to say, these measurements will shed light on the underlying mechanism for hadronic B decays and provide important information on form factors and unitarity angles, for example.

In general it is a difficult task to compute hadronic matrix elements. Recently, it has been shown that, in the heavy quark limit, the hadronic matrix elements for two-body hadronic B decays can be computed from first principles and expressed in terms of form factors and meson light-cone distribution amplitudes. Nonfactorizable diagrams in the heavy quark limit are dominated by hard gluon exchange and thus can be calculated as expansion in terms of the strong coupling constant. In this talk I will discuss the merit and some issues of the QCD-improved factorization approach and apply it to some B decay modes.