The Theory of the Nucleon Spin

I discuss two topics of current interest in the study of the spin structure of the nucleon. First, I discuss whether there is a sum rule for the components of the nucleon's angular moments. Second, I discuss the measurement of the nucleon's transversity distribution in light of recent results reported by the HERMES collaboration at DESY.Comment: 15 pages, 8 figures, LaTeX using rspublic.cls and BoxedEPS macros; as submitted to Phil Trans A of the Royal Society for forthcoming volume: The Quark Structure of Matter; email correspondence to [email protected]

Light and Gravity Effects on Adenine Nucleotide Content and Energy Charge in Maize Roots

Two millimeter apical segments of maize (cv. LG 11) primary roots were analysed in relation to the effects of light and gravity on adenine nucleotide content. Adenosine triphosphate (ATP) content is very sensitive to these stimuli. ATP levels are lower in roots exposed to light than in those kept in the dark. The energy charge (E.C.) decreases markedly after exposure to light and gravity. For the vertical roots E.C. is stable. Present data confirm the fact that light and gravity may act on cell metabolism, modifying the energy requirements. This will be discussed in relation to some hormone action

QCD and Hadron Dynamics

Perturbative QCD predicts and describes various features of multihadron production. An amazing similarity between observable hadron systems and calculable underlying parton ensembles justifies the attempts to use the language of quarks and gluons down to small momentum scales, to approach the profound problems that are commonly viewed as being entirely non-perturbative.Comment: Talk at the Royal Society meeting "Structure of Matter", London, May 200

Photon Structure and Quantum Fluctuation

Photon structure derives from quantum fluctuation in quantum field theory to fermion and anti-fermion, and has been an experimentally established feature of electrodynamics since the discovery of the positron. In hadronic physics, the observation of factorisable photon structure is similarly a fundamental test of the quantum field theory Quantum Chromodynamics (QCD). An overview of measurements of hadronic photon structure in e+e- and ep interactions is presented, and comparison made with theoretical expectation, drawing on the essential features of photon fluctuation into quark and anti-quark in QCD.Comment: 29 pages, 15 figures, to appear in Philosophical Transactions of the Royal Society of London (Series A: Mathematical, Physical and Engineering Sciences

CMS Barrel Pixel Detector Overview

The pixel detector is the innermost tracking device of the CMS experiment at the LHC. It is built from two independent sub devices, the pixel barrel and the end disks. The barrel consists of three concentric layers around the beam pipe with mean radii of 4.4, 7.3 and 10.2 cm. There are two end disks on each side of the interaction point at 34.5 cm and 46.5 cm. This article gives an overview of the pixel barrel detector, its mechanical support structure, electronics components, services and its expected performance.Comment: Proceedings of Vertex06, 15th International Workshop on Vertex Detector

An experimental investigation of the photoproduction of pi+ mesons from hydrogen near threshold

This thesis describes the experimental work carried out by the author from 1953 to 1931 on the investigation of the photoproduction of pi+ mesons from hydrogen near threshold. The research was motivated by the lack of experimental measurements in the low energy region verifying the predicted threshold energy dependence given by Dispersion Relations and the violation in the well known connection between the low energy pion interactions. Chapter I provides a summary of the theoretical attempts to describe the photoproduction of pions from hydrogen and gives a detailed study of the field of low energy plon photoproduction. Chapter II is a review of previous experimental methods and results in the field of low energy plon photoproduction, and illustrates the necessity of an accurate set of experimental results in the low energy region. Chapter III describes the construction of a specially designed, pressure compensated thin-walled liquid hydrogen target, for the detection of low energy pions. The construction and operation of the target and the compensator design was carried out by the author. The initial design or the target was carried out in collaboration with Dr. W. Hogg. Chapter IV describes two methods of detecting mesons, one by a time of flight method and the other by a delayed coincidence technique. The construction and testing of the time of flight telescope were carried out by the author and the experiment was performed In collaboration with Drs. G.H. Lewis and H.E. Asuma. Preliminary tests on the delayed coincidence technique previously developed by Drs. G.Z. Lewis and R.E. Azuma were carried out by the author using a thin polythene target. Chapter V contains a description of the threshold meson experiment which provides the most accurate Information showing the non-linear threshold energy dependence of the cross-section. The author was responsible for the operation of the liquid hydrogen target during the complete experiment which was of three weeks duration, while the operation, monitoring and collection of the experimental data was shared with Drs. G.H. Lewis. R.S. Asuraa and Dr D. Leith. The analysis of the results have been evaluated independently by the author. The thesis concludes with a discussion of the present state of the knowledge in the field of low energy pion physios

Quelle place pour la relation esthétique dans l’enseignement de la lecture littéraire ?

Depuis quelques années, tant au sein des études littéraires qu’en didactique de la littérature, en anthropologie, en sociologie ou en esthétique, des voix s’élèvent qui voudraient replacer la littérature dans la vie. La lecture n’est plus tant « une tâche active de déchiffrement », un travail « de comblement des blancs et des lacunes du texte », mais plutôt une expérience sensible et singulière au cours de laquelle un sujet (lecteur) éprouve des « manières d’être » qui vont l’affecter, le con..

Entwicklung der vier Dimensionen der Laufbahnadaptabilität bei Jugendlichen in einem Motivationssemester : welchen Einfluss auf die Jugendlichen haben die in einem Motivationssemester involvierten Bezugspersonen hinsichtlich der vier Dimensionen der Laufbahnadaptabilität?

Die vorliegende Masterarbeit befasst sich mit der Laufbahnadaptabilität von Jugendlichen, die ein Motivationssemester als Brückenangebot für den Berufseinstieg in die Lehre besuchten. Im Rahmen der Untersuchung geht es darum, zu eruieren, welchen Einfluss die in ein Motivationssemester involvierten Bezugspersonen der Jugendlichen auf die vier Dimensionen der Laufbahnadaptabilität Laufbahnplanung, Exploration und Reflexion, Selbstvertrauen sowie Entscheidungsbereitschaft haben. Auf der Grundlage einer Literaturrecherche sowie leitfadengestützten Interviews mit Teilnehmenden des Motivationssemesters JOB PLUS der Stadt Zürich zeigt die Arbeit auf, dass durch die Bezugspersonen ein positiver Einfluss auf die Laufbahnadaptabilität stattgefunden hat. Dieser fällt für die vier Dimensionen unterschiedlich stark aus. So zeigen sich bei den beiden Dimensionen Exploration und Reflexion sowie Selbstvertrauen sehr starke Ausprägungen, was den Einfluss durch die Bezugspersonen anbelangt, wohingegen die beiden anderen Dimensionen Laufbahnplanung sowie Entscheidungsbereitschaft eine schwächere Ausprägung aufweisen