The vacuum preserving Lie algebra of a classical W-algebra

We simplify and generalize an argument due to Bowcock and Watts showing that one can associate a finite Lie algebra (the `classical vacuum preserving algebra') containing the M\"obius $sl(2)$ subalgebra to any classical \W-algebra. Our construction is based on a kinematical analysis of the Poisson brackets of quasi-primary fields. In the case of the \W_\S^\G-algebra constructed through the Drinfeld-Sokolov reduction based on an arbitrary $sl(2)$ subalgebra $\S$ of a simple Lie algebra \G, we exhibit a natural isomorphism between this finite Lie algebra and \G whereby the M\"obius $sl(2)$ is identified with $\S$.Comment: 11 pages, BONN-HE-93-25, DIAS-STP-93-13. Some typos had been removed, no change in formula

New N=1 Extended Superconformal Algebras with Two and Three Generators

In this paper we consider extensions of the super Virasoro algebra by one and two super primary fields. Using a non-explicitly covariant approach we compute all SW-algebras with one generator of dimension up to 7 in addition to the super Virasoro field. In complete analogy to W-algebras with two generators most results can be classified using the representation theory of the super Virasoro algebra. Furthermore, we find that the SW(3/2, 11/2)-algebra can be realized as a subalgebra of SW(3/2, 5/2) at c = 10/7. We also construct some new SW-algebras with three generators, namely SW(3/2, 3/2, 5/2), SW(3/2, 2, 2) and SW(3/2, 2, 5/2).Comment: 30 pages (Plain TeX), BONN-HE-92-0

A self adjustment technique minimizing channel to channel variations in VLSI readout chips

Modern VLSI readout chips for strip and pixel detectors contain many electronic channels which all should behave exactly alike in order to give the optimal performance. However, good matching is often very difficult to achieve due to many design constraints. In this paper, a simple concept for automatic adjustment of important VLSI circuit properties simultaneously in all readout channels is presented. The tuning is performed by applying a test injection pulse and, if necessary, a reference signal to all cells simultaneously. A simple circuit in each channel adjusts the control voltage on a storage capacitor until matching is optimal. An application of this concept in a self adjusting delay circuit is presented and other possible applications are discussed. (orig.)SIGLEAvailable from TIB Hannover: RN 5063(95-04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany); Ministerium fuer Wissenschaft und Forschung des Landes Nordrhein-Westfalen, Duesseldorf (Germany)DEGerman

ELSA A new experimental facility at Bonn

SIGLETIB: RN 4852 (85-12) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Universitaet Bonn, Physikalisches Institut. Jahresbericht 1996-97

Available from TIB Hannover: RR 8054(98-04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Messung der Temperatur und des Aerosolgehaltes in der polaren Stratosphaere Abschlussbericht

From August 1989 through July 1992 under this project a lidar was setup in Northern Norway using existing infrastructure (observatory with a 1-m telescope), and measurements of the aerosol content of the stratosphere were conducted. As the lidar is permanently installed in this observatory in Northern Norway, the technical further development of this instrument involves switching over between design, procurement and construction phases at Bonn and practical testing phases on Andoya. Details have been described in earlier reports and are therefore rendered here in a summarized form. (orig./AKF)Es wurde in diesem Vorhaben vom August 1989 bis Juli 1992 ein Lidar in Nordnorwegen unter Ausnutzung vorhandener Infrastruktur (Observatorium mit 1-m Teleskop) aufgebaut, sowie Messungen des Aerosolgehalts der Stratosphaere durchgefuehrt. Da das Lidar permanent in diesem Observatorium in Nordnorwegen installiert ist, entsteht bei der technischen Fortentwicklung des Instruments ein Wechsel zwischen Konstruktions-, Beshaffungs- und Bauphasen in Bonn und praktischen Erprobungsphasen auf Andoya. Die Einzelheiten sind in frueheren Berichten detailliert beschrieben und werden daher hier nur noch zusammengefasst wiedergegeben. (orig.)SIGLEAvailable from TIB Hannover: F95B36 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Universitaet Bonn, Physikalisches Institut. Jahresbericht 1998-99

Available from TIB Hannover: RR 8054(00-02) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Universitaet Bonn, Physikalisches Institut. Jahresbericht 1994-95

Available from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Jahresbericht. Physikalisches Institut, Universitaet Bonn. 1984-85

SIGLETIB: ZN 9878 (1984/85) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A method to determine the electroweak mixing angle from Z decays to tau leptons using optimal observables

We propose a new method to measure the electroweak mixing angle in Z decays to tau leptons. For various tau decay channels optimal observables are constructed which yield the largest possible signal-to-noise ratio. These optimal observables are derived from the full spin-density-matrix of the process including correlations between tau spins and an approximation to the tau flight direction. (orig.)24 refs.SIGLEAvailable from TIB Hannover: RN 5063(97-05) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman