Aharonov-Bohm Problem for Spin-One

The basic AB problem is to determine how an unshielded tube of magnetic flux $\Phi$ affects arbitrarily long-wavelength charged particles impinging on it. For spin-1 at almost all $\Phi$ the particles do not penetrate the tube, so the interaction essentially is periodic in $\Phi$ (AB effect). Below-threshold bound states move freely only along the tube axis, and consequent induced vacuum currents supplement rather than screen $\Phi$. For a pure magnetic interaction the tube must be broader than the particle Compton wavelength, i.e., only the nonrelativistic spin-1 AB problem exists.Comment: 15 pages, Late

Characterization of fractional-quantum-Hall-effect quasiparticles

Composite fermions in a partially filled quasi-Landau level may be viewed as quasielectrons of the underlying fractional quantum Hall state, suggesting that a quasielectron is simply a dressed electron, as often is true in other interacting electron systems, and as a result has the same intrinsic charge and exchange statistics as an electron. This paper discusses how this result is reconciled with the earlier picture in which quasiparticles are viewed as fractionally-charged fractional-statistics ``solitons". While the two approaches provide the same answers for the long-range interactions between the quasiparticles, the dressed-electron description is more conventional and unifies the view of quasiparticle dynamics in and beyond the fractional quantum Hall regime.Comment: 11 pages, latex, no figure

Ridge Production in High-Multiplicity Hadronic Ultra-Peripheral Proton-Proton Collisions

An unexpected result at the RHIC and the LHC is the observation that high-multiplicity hadronic events in heavy-ion and proton-proton collisions are distributed as two "ridges", approximately flat in rapidity and opposite in azimuthal angle. We propose that the origin of these events is due to the inelastic collisions of aligned gluonic flux tubes that underly the color confinement of the quarks in each proton. We predict that high-multiplicity hadronic ridges will also be produced in the high energy photon-photon collisions accessible at the LHC in ultra-peripheral proton-proton collisions or at a high energy electron-positron collider. We also note the orientation of the flux tubes between the quark and antiquark of each high energy photon will be correlated with the plane of the scattered proton or lepton. Thus hadron production and ridge formation can be controlled in a novel way at the LHC by observing the azimuthal correlations of the scattering planes of the ultra-peripheral protons with the orientation of the produced ridges. Photon-photon collisions can thus illuminate the fundamental physics underlying the ridge effect and the physics of color confinement in QCD.Comment: Presented by SJB at Photon 2017: The International Conference on the Structure and the Interactions of the Photon and the International Workshop on Photon-Photon Collisions. CERN, May 22-26, 2017. References adde

Investigation of potential industrial uses for tools assessing saliency and clutter of design features

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 20).As human interaction with digital displays becomes an indispensable part of everyday life, user Interface (UI) design is becoming an increasingly important field. There is a great demand in industry for tools to aid designers in UI design, and in response to this need, a perceptual tool, DesignEye, has been developed. DesignEye creates maps of saliency and clutter within an image, which can be used by designers to find problem areas in a design. The experiment described here tested how subjects differ in their analysis of existing UT designs when they have also been given access to maps from DesignEye. Subjects were asked to evaluate existing designs in Ford vehicles for three conditions: (i) while being given no assistance, (ii) while being asked to use a design technique like squinting, and (iii) while being asked to use DesignEye output. It was found that subjects did not substantially differ in their analysis when given a perceptual tool. However, due to the backgrounds of the subjects tested and the experimental setup and environment, further testing is necessary to determine how DesignEye might change the way designers analyze designs, build consensus within teams, and objectively rate potential design options.by Tanya S. Goldhaber.S.B