Helicity analysis of vector mesons produced in proton-dissociative diffractive photoproduction at large momentum transfer at HERA

The proton-dissociative photoproduction of vector mesons #gamma#p #-># V N has been measured in e"+p interactions at HERA with the ZEUS detector. The integrated luminosity of the data sample under study was 24 pb"-"1. The data was collected at the photon-proton center-of-mass energy of W_#gamma#_p #approx#100 GeV and with the four-momentum transfer in the proton vertex ranging up to -t=12 GeV"2. As a result of the decay angular analysis the spin density matrix elements for the #rho#"0, #phi# and J/#psi# mesons were determined in the wide -t range available. The obtained results are compared to the expectations of pQCD calculations. (orig.)SIGLEAvailable from TIB Hannover: RA 8913(2002-033) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Vector meson photoproduction at large momentum transfer at HERA

This thesis reports on a study of elastic and proton-dissociative production of #rho#"0, #phi#, and J/#psi# vector mesons (ep#->#eVp, ep#->#eVN) at the positron-proton collider HERA. The data cover the kinematic range 85<W<105 GeV and Q"2<0.01 GeV"2. The low values of Q"2 covered made it possible to extract from the data the cross sections for real photoproduction of vector mesons (#gamma#p#->#Vp, #gamma#p#->#VN) up to -t=3 GeV"2. In the case of #rho#"0 (#rho#"0#->##pi#"+#pi#"-) production, the #pi#"+#pi#"- invariant mass distribution has been investigated as a function of t. The spectra show deviations from a simple relativistic Breit-Wigner shape as expected in models in which the asymmetry of the #pi#"+#pi#"- invariant mass shape is ascribed to the interference of resonant and non-resonant #pi#"+#pi#"- production. The asymmetry of the #rho#"0 mass shape decreases with increasing -t. The spin density matrix elements obtained from the decay angular distribution of #rho#"0, #phi# and J/#psi# mesons are generally consistent with expectations based on s-channel helicity conservation, except for the highest -t range accessible in this analysis where r_1_-_1"0"4 was found to be different from zero for all mesons. The differential cross sections d#sigma#/dt for elastic and proton-dissociative #rho#"0, #phi# and J/#psi# production have been measured. The pomeron trajectory has been determined from the study of the W dependence od d#sigma#/dt at fixed t for #rho#"0 and #phi# mesons in the range 0.0<-t<0.9 GeV"2 and 0.0<-t<1.4 GeV"2 respectively. From elastic #rho#"0 photoproduction the result is #alpha#_P(t)=(1.08#+-#0. 02)+(0.11#+-#0.04)t and from that of #phi# data #alpha#_P(t)=(1.08#+-#0.01)+(0.15#+-#0.04)tAvailable from TIB Hannover: RR 8919(1999-045) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Structures, problems, potentials, and future perspectives of engineering education in Poland

'The joint Polish-German research project 'General structures, problems, potentials and future perspectives of engineering education in Poland' funded by the German VW-Foundation (Volkswagen Stiftung) aimed at carrying out an analysis of structural developments within the higher education system for engineering in Poland during the last decade. Before starting and after finishing each phase of the joint project, three mutually prepared seminars took place which focused on different topic that helped preparing the next step and discussing the outcomes of the preceding phases. The introduction seminar took place in Crakow, the mid-term seminar which is documented here proceeded in Zakopane and the final seminar was held in Kassel. As the project aimed mainly towards a better understanding of the transformation process of the important national subsystem of higher engineering education one has to observe also its relationship to other polish subsidiary systems (i.e. labour market, industrial and technological development). Polish higher engineering education is on its way to modernization. Resulting from the 1990's new higher education laws there is a trend towards stronger integration into European and international higher education systems for engineers. Interactions and interdependencies with other national subsystems - politics, economy and industry - particularly within the research-, development-, and production-sector - were one main focus of the analysis. The research project is conducted as a bi-national joint project consisting of two teams with four scientists each, and one national co-ordinator among each team therefore all three seminars had participants and contributors from both countries. For the conduct of the survey competent reporters at the individually included universities had been attracted, who prepared mainly the so-called institutional reports of each higher institute for engineering education in Poland bound to a detailed questionnaire of special questions concerning the structures, potentials and future trends within the Polish higher engineering education.' (extract). Contents: Part I - existing structures: Wojciech Batko, Antoni Kalukiewicz: Evaluation of the development of the engineering education system (23-28); Maria Wladyslawa Francuz: Quality management in engineering education (29-33); Krzysztof Gasidlo: Practical training in engineering education. Based on experiences from the Politechnika Slaska w Gliwicach (34-41); Danuta Anita Wozniak: Health aspects in engineering education (42-44). Part II: new developments: Antoni Kalukiewicz, Wojciech Batko: Development of organizational and decisional structures in Polish technical universities (47-54); Zygmunt Drzymala: Development of a new cooperation system between technical universities and industry (55-60); Baerbel Gruenig: Developing new curricula in Polish engineering education (61-67); Janusz Piechocki: Restructuring process of engineering education at the Warminsko-Mazurski University in Olsztyn (68-71); Helmut Winkler: Organisational and structural changes in Polish engineering education - impressions from institutional reports (72-82). Part III: future perspectives: Jozef Flizikowski: Future perspectives of engineering education (85-100); Andrzej Kaczmarczyk: Perspectives of engineering education - certain questions (101-102); Marzena Wilamowska-Korsak: Perspectives of engineering education at the Warmia-Mazurian University in Olsztyn (103-106); Janusz Szpytko: Engineering challenges (107-110)Inhaltsverzeichnis: Part I - existing structures: Wojciech Batko, Antoni Kalukiewicz: Evaluation of the development of the engineering education system (23-28); Maria Wladyslawa Francuz: Quality management in engineering education (29-33); Krzysztof Gasidlo: Practical training in engineering education. Based on experiences from the Politechnika Slaska w Gliwicach (34-41); Danuta Anita Wozniak: Health aspects in engineering education (42-44). Part II: new developments: Antoni Kalukiewicz, Wojciech Batko: Development of organizational and decisional structures in Polish technical universities (47-54); Zygmunt Drzymala: Development of a new cooperation system between technical universities and industry (55-60); Baerbel Gruenig: Developing new curricula in Polish engineering education (61-67); Janusz Piechocki: Restructuring process of engineering education at the Warminsko-Mazurski University in Olsztyn (68-71); Helmut Winkler: Organisational and structural changes in Polish engineering education - impressions from institutional reports (72-82). Part III: future perspectives: Jozef Flizikowski: Future perspectives of engineering education (85-100); Andrzej Kaczmarczyk: Perspectives of engineering education - certain questions (101-102); Marzena Wilamowska-Korsak: Perspectives of engineering education at the Warmia-Mazurian University in Olsztyn (103-106); Janusz Szpytko: Engineering challenges (107-110)German title: Strukturen, Probleme, Potentiale und Perspektiven der Ingenieurausbildung in PolenSIGLEAvailable from http://www.uni-kassel.de/wz1/v pub/v ap35.pdf / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A new experiment for the HERA collider expression of interest

We first review the physics topics which we consider to be the highlights of the proposed program. The increased sensitivity to the correct understanding of radiation in strong interactions is made clear in these sections. We then describe some first ideas on what the optimized detector for this physics would look like. We note that the physics described in the following sections cannot be carried out with HERA-II. This second phase of HERA running is focused on high Q"2 physics, which requires high luminosities. These are achieved by placing combined dipole/quadrupole magnets very near the H1 and ZEUS interaction points, thus limiting access to the small-x, low Q"2 physics which would be a central element in the proposed program. Also, many of the topics one would like to study require a different type of detector than the current H1 and ZEUS detectors. We close with a brief discussion of a possible time scale for the construction of a new detector and what we would consider to be a viable running plan. (orig.)Available from TIB Hannover: RR 2916(03-62) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Untersuchung der Eigenschaften des 9%-Chromstahles vom Typ 9Cr-0.5Mo-1.8W-V-Nb im Hinblick auf seine Verwendung als Rohrleitungs- und Kesselbaustahl unter erhoehten Temperaturen

In einem umfangreichen experimentellen Versuchsprogramm wurden nach unterschiedlicher Waermebehandlung an zwei Schmelzen des wolframhaltigen 9% Cr-Stahles (NF 616) die Gefuegeausbildung und die Festigkeits- und Zaehigkeitseigenschaften sowie das Kriechdehn- und Zeitstandverhalten des Grundwerkstoffes und des im Hinblick auf die WEZ-Erweichungszone schweisssimulierten Gefueges ermittelt und mit der Schweissverbindung aus NF 616- bzw. E 9 1 1-aehnlichem Schweissgut verglichen. Ausserdem wurden die Zaehigkeit des Schweissguts und der WEZ in den Schweissverbindungen sowie die Versproedungsneigung der Grobkornzone der WEZ in Schweisssimulationsversuchen untersucht. Neben der Verteilung und Groesse der Gefuegeausscheidungen (M_2_3C_6, MX, Laves-Phase) stellt sich die Versetzungsdichte als der wesentlichsten, die Langzeiteigenschaften kennzeichnender Gefuegeparameter heraus. Waermebehandlungstemperaturen knapp oberhalb des A_c_1-Punktes fuehren bereits im Sekundenbereich (entspricht der WEZ-Erweichungszone) zu deutlichen Einbussen des Kriechwiderstandes gegenueber dem Grundwerkstoff, woraus sich eine Neigung zur Typ IV-Rissbildung fuer die Schweissnaht ableiten laesst. In Abhaengigkeit der Pruefspannung zeigt sich ein unterschiedliches Kriechverhalten, ausgedrueckt durch den Norton-Kriechexponenten (16 fuer hohe und 6 fuer niedrige Spannungen). Dies ist bei der Langzeitextrapolation zu beachten, weil es ansonsten bei einem Uebergewicht einer Datenbasis mit hohen Spannungen zu einer Fehleinschaetzung kommen kann. Waehrend sich das NF 616-aehnliche Schweissgut bei Raumtemperatur noch als relativ sproede erweist, trifft dies fuer die Grobkornzone der WEZ nicht zu. Eine Anlassgluehung der Schweissnaht bewirkt keine Versproedung. Der untersuchte Stahl ist grundsaetzlich bis zu einer Temperatur von ca. 620 C als Kessel- und Rohrleitungsstahl verwendbar. (orig.)In an extensive testing programme, the microstructure, tensile and impact properties, creep behaviour and the stress rupture strength to two heats of the tungsten-containing 9% chromium steel NF616 have been investigated. The creep rupture properties of weldments, on with a matching filler and another with a filler of composition similar to that of the steel E 9 1 1, and of weld simulations of the softented heat affected zone were determined and compared with those of the basis steel. The toughness of the weld metal and the HAZ of weldments was also investigated. The tendency for embrittlement of the coarse grained HAZ was assessed using weld simulation specimens. Alongside the size and distribution of precipitates (M_2_3C_6, MX and Laves phase), the dislocation density was found to be the most significant structural parameter with respect to the long term strength properties. Tempering at temperatures just above the A_c_1 temperature, even for only a few deconds as used in the softened HAZ weld simulation, led to a considerable decrease in the creep resistance compared with the normal heat treatment, which explains the susceptibility of weldments to type IV cracking in creep tests. The creep behaviour depended on the applied stress, a Norton stress exponent of 16 being found for the high stress region and 6 for the low stress region. This observation must be taken into account in the extrapolation of data to long times; an overemphasis on test data obtained at high stresses can lead to an overestimation of the stress rupture strength. Although the weld metal of the matching filler weldment was found to be relatively brittle at room temperature, the coarse grained HAZ impact strength was high. A post weld heat treatment did not lead to embrittlement. The steel investigated may be used as boiler tubes and steam pipes operating at temperatures up to 620 C. (orig.)Dissertation submitted by O. WachterAvailable from TIB Hannover: RA 831(3074) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

First measurements of HERA luminosity by ZEUS lumi monitor

SIGLEAvailable from TIB Hannover: RA 2999(92-066) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Production of charged hadrons by positive muons on deuterium and xenon at 490 GeV

Results on the production of charged hadrons in muon-deuteron and muon-xenon interactions are presented. The data were taken with the E665 spectrometer, which was exposed to the 490 GeV muon beam of the Tevatron at Fermilab. The use of a streamer chamber as vertex detector provides nearly 4#pi# acceptance for charged particles. The #mu#D data are compared with the #mu#Xe data in terms of multiplicity distributions, average multiplicities, forward-backward multiplicity correlations, rapidity and transverse momentum distributions and of two-particle rapidity correlations of charged hadrons. The data cover a range of invariant hadronic masses W from 8 to 30 GeV. (orig.)Available from TIB Hannover: RR 2916(93-17) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Recent photoproduction results from ZEUS

Recent results for inclusive jet cross sections, dijet cross sections and dijet angular distributions are compared with NLO perturbative QCD calculations. The observation of isolated high PT photons (prompt photons) is also reported

F-2(D(3)) measurements at ZEUS

Results on the diffractive structure function F-2(D(3)) in deep inelastic neutral current positron-proton scattering (DIS) have been obtained by the ZEUS collaboration using two different methods. Diffractive interactions are selected by either requiring a small, not exponentially suppressed invariant hadronic mass M-X in the main detector or by detecting a fast proton in the ZEUS leading proton spectrometer (LPS). The results of the two methods are compared

Event shape analysis of multihadronic final states in deep inelastic rapidity gap events at HERA

A global event shape analysis of the multihadronic final states observed in deep inelastic scattering (DIS) with a large forward rapidity gap (LRG) is performed in the range Q(2) greater than or equal to 5 GeV2, 160 GeV less than or equal to W less than or equal to 250 GeV and eta(max) less than or equal to 1.8. Particular emphasis is paid to the dependence of these variables, measured in the gamma*-pomeron rest frame, upon M-X, the mass of the hadronic final state. With increasing M-X the multihadronic final states become planar. The broadening effects exhibited by the data can be described by including a gluon density in models where the pomeron has a partonic structure or alternatively by considering a direct coupling of the pomeron to quark and gluon pairs