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A new MICROMEGAS detector readout scheme that protects the readout electronics from damage caused by discharge initiated by large gas amplification has been studied. In the new method, the signal is produced by a readout plane placed below the MICROMEGAS detector anodes. The ratio of the signal amplitude on the readout plane was more than 65% of the signal amplitude on the cathode of the MICROMEGAS. (C) 2003 Elsevier Science B.V. All rights reserved.
Inclusive jet production, e+e(-) --> e(+)e(-) jet X, is studied using 560 pb(-1) of data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 209 GeV. The inclusive differential cross section is measured using a k(1), jet algorithm as a function of the jet transverse momentum, p(t), in the range 3 < p(t) < 50 GeV for a pseudorapidity, eta, in the range -1 < eta < 1. This cross section is well represented by a power law. For high p(t), the measured cross section is significantly higher than the NLO QCD predictions, as already observed for inclusive pi(+/-) and pi(0) production. (C) 2004 Published by Elsevier B.V.
A Higgs particle produced in association with a Z boson and decaying into weak boson pairs is searched for in 336.4 pb(-1) of data collected by the L3 experiment at LEP at centre-of-mass energies from 200 to 209 GeV. Limits on the branching fraction of the Higgs boson decay into two weak bosons as a function of the Higgs mass are derived. These results are combined with the L3 search for a Higgs boson decaying to photon pairs. A Higgs produced with a Standard Model e(+)e- --> Zh cross section and decaying only into electroweak boson pairs is excluded at 95% CL for a mass below 107 GeV. (C) 2003 Published by Elsevier B.V.
In the course of a casual conversation during a social gathering, in the spring of 1974, we were discussing some recent developments in the area of diffraction from perfect crystals, namely, interferometry in the Angstrom region. I (R.C.) was asked by Al Overhauser whether or not I knew anything about the subject. "Not much" was my answer, "but I can read some papers". Al then proceeded to describe a possible experiment, namely, the effect of gravity on the quantum mechanical phase of the neutron, in essence, what later was called the COW experiment (Colella, Overhauser, Werner).
This letter presents experimental evidence that the electrical conductance of a single molecule can be altered by a chemical binding event. Self-assembled monolayers of electron donor tetramethyl xylyl dithiol (TMXYL) have been synthesized and chemically switched to a conducting state by reaction with an electron acceptor tetracyanoethylene (TCNE). Low bias conductance measurements obtained by scanning tunneling spectroscopy under ultrahigh vacuum conditions show a change from insulating to ohmic behavior as a result of the electron donor/acceptor interaction.
Hamaker constants are characteristic material properties that determine the magnitude of the nonlinear van der Waals force between atoms, molecules and nanoscale aggregates of atoms. This paper explores the novel possibility of using Harmonic Balance based nonlinear system identification methods to extract from the nonlinear vibration spectrum Of resonant atomic force silicon microcantilevers, the Hamaker constants between a few atoms at the tip of the microcantilever and graphite, gold and silicon carbide samples. First, the nonlinear dynamics of a diving board microcantilever coupled to the samples through van der Waals force potentials are investigated through a discretized model of the system. Next, the feasibility, of using Harmonic Balance based nonlinear system identification techniques are demonstrated using simulations of the ...
Two-wave mixing in a dynamic holographic film acts as the adaptive beam combiner in a short-coherence interferometer that performs optical coherence-domain reflectometry (OCDR) through turbid media. This approach combines the high spatial resolution and sensitivity of coherence-domain reflectometry with photorefractive quantum-well-based adaptive homodyne detection. A depth resolution of 28 p,m and penetration through 16 mean free paths in a turbid medium have been obtained in this adaptive OCDR application. (C) 2003 Optical Society of America.
ICE-TheOREM was a project which made several important contributions to the repository domain, promoting deposit by integrating the repository with authoring workflows and enhancing open access, by adding new infrastructure to allow fine-grained embargo management within an institution without impacting on existing open access repository infrastructure. In the area of scholarly communications workflows, the project produced a complete end-to-end demonstration of eScholarship for word processor users, with tools for authoring, managing and disseminating semantically-rich thesis documents fully integrated with supporting data. This work is focused on theses, as it is well understood that early career researchers are the most likely to lead the charge in new innovations in scholarly publishing and dissemination models. The authoring tools...
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