Production inclusive de hadrons dans les collisions de deux photons au sein de l'expérience L3 PDF Download

Author: Pablo Achard
Publisher:
ISBN:
Category :
Languages : fr
Pages : 213

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La production inclusive de pions neutres, de particules chargées et de jets par des collisions de deux photons quasi-réels est étudiée à l'aide du détecteur L3 à LEP. Les données présentent une section efficace à grande impulsion transverse beaucoup plus élevée que ne le prédisent les calculs de QCD au deuxième ordre. Après une description détaillée du cadre théorique et expérimental, cette thèse explique de manière approfondie l'analyse des données. Celles-ci sont étudiées en fonction de l'impulsion et de la pseudo-rapidité. Différentes paramétrisations sont proposées. Les données sont en bon accord avec des résultats précédemment publiés mais, en étendant les intervalles de mesure, permettent de mettre à jour un désaccord - jusqu'à présent inexpliqué - avec les prédictions théoriques.

Author: Bertrand Echenard
Publisher:
ISBN:
Category :
Languages : fr
Pages : 207

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Cette thèse présente une étude de la production de baryons dans les collisions à deux photons effectuée au CERN sur l'expérience L3. La première partie est consacrée à l'étude de la production inclusive de baryons [Lambda], [Xi]−, [Xi]0(1530) et [Omega]−. Les données sont comparées aux prédictions de plusieurs générateurs Monte Carlo ainsi qu'aux mesures obtenues dans les réactions d'annihilation électron-positron. La seconde partie est dédiée à l'analyse de la production exclusive de paires proton-antiproton, lambda-antilambda et sigma0-antisigma0. Aucun des différents modèles théoriques actuels (trois quarks, quark-diquark, échanges de pôles...) ne parvient à reproduire la totalité des résultats. Une recherche sur la production de baryons exotiques, le pentaquark [theta]+, est finalement présentée dans la partie finale. Aucun signal n'est observé et une limite supérieure sur la production de pentaquark est calculée.

Author: Ákos Csilling
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The phenomenology of hadron and photon reactions at short distances is discussed in terms of perturbative quantum chromodynamics. In addition to large P/sub T/ hadron reactions, predictions are reviewed for jet production in two photon collisions, the relation of photon and gluon jet production, hadronic production and color separation, upsilon decay into hadrons and photons, leading particle distributions in low P/sub T/ hadron collisions, discriminants of quark and gluon jets, and the effects of coherence on gluon distributions in hadrons. A number of new experimental tests of QCD are discussed.

Author: G. Franco Bassani
Publisher: Springer Science & Business Media
ISBN: 3642884210
Category : Science
Languages : en
Pages : 360

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Atomic hydrogen, the simplest of all stable atoms, has been a challenge to spectroscopists and theoreticians for many years. Here, as in similar systems like positronium, muonium and possibly helium, the accuracy of theoretical predictions is comparable to that of experimental measurements. Hence exciting confrontations are possible. This together with expected large experimental improvements explains the strong interest in the symposium held in Pisa in June-July 1988. The resulting book completely covers the precision spectroscopy of atomic hydrogen and hydrogen-like systems, and also discusses aspects of QED and the influence of strong fields.

Author: J. Leite Lopes
Publisher: Elsevier
ISBN: 1483278972
Category : Science
Languages : en
Pages : 501

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Gauge Field Theories: An Introduction covers the basic notions and principles of gauge theories. This book is composed of 10 chapters that focus on the Salam-Weinberg model of electro-weak interactions of neutrino-lepton scattering, as well as the Parton model. The first chapter is an introduction to solitons and instantons, as well as the topological quantum numbers, subjects that arose from the study of the non-linear field equations in gauge theories. The succeeding chapters deal with the concept of gravitational field, electrodynamical systems, the Yang-mills gauge fields, and the Higgs mechanism. The remaining chapters highlight the speculations on possible lepton and quark structured. These chapters present the SU(5) model of grand unification. This book will prove useful to physics university and advanced high school students.

Author: V. N. Gribov
Publisher: Cambridge University Press
ISBN: 1139441892
Category : Science
Languages : en
Pages : 311

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This 2003 book is a rigorous introduction to the theory of complex angular momenta, based on the methods of field theory. This is an English translation of the famous lecture course given by Vladimir Gribov in 1969. Besides their historical significance, these lectures are highly relevant to modern research in theoretical physics.

Author: Erik De Schutter
Publisher: National Geographic Books
ISBN: 0262013274
Category : Medical
Languages : en
Pages : 0

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A guide to computational modeling methods in neuroscience, covering a range of modeling scales from molecular reactions to large neural networks. This book offers an introduction to current methods in computational modeling in neuroscience. The book describes realistic modeling methods at levels of complexity ranging from molecular interactions to large neural networks. A “how to” book rather than an analytical account, it focuses on the presentation of methodological approaches, including the selection of the appropriate method and its potential pitfalls. It is intended for experimental neuroscientists and graduate students who have little formal training in mathematical methods, but it will also be useful for scientists with theoretical backgrounds who want to start using data-driven modeling methods. The mathematics needed are kept to an introductory level; the first chapter explains the mathematical methods the reader needs to master to understand the rest of the book. The chapters are written by scientists who have successfully integrated data-driven modeling with experimental work, so all of the material is accessible to experimentalists. The chapters offer comprehensive coverage with little overlap and extensive cross-references, moving from basic building blocks to more complex applications. Contributors Pablo Achard, Haroon Anwar, Upinder S. Bhalla, Michiel Berends, Nicolas Brunel, Ronald L. Calabrese, Brenda Claiborne, Hugo Cornelis, Erik De Schutter, Alain Destexhe, Bard Ermentrout, Kristen Harris, Sean Hill, John R. Huguenard, William R. Holmes, Gwen Jacobs, Gwendal LeMasson, Henry Markram, Reinoud Maex, Astrid A. Prinz, Imad Riachi, John Rinzel, Arnd Roth, Felix Schürmann, Werner Van Geit, Mark C. W. van Rossum, Stefan Wils

Author: C.P. Enz
Publisher: Springer Science & Business Media
ISBN: 9401022747
Category : Language Arts & Disciplines
Languages : en
Pages : 568

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This collection of essays is intended as a tribute to Josef Maria Jauch on his sixtieth birthd~. Through his scientific work Jauch has justly earned an honored name in the community of theo retical physicists. Through his teaching and a long line of dis tinguished collaborators he has put an imprint on modern mathema tical physics. A number of Jauch's scientific collaborators, friends and admirers have contributed to this collection, and these essays reflect to some extent Jauch's own wide interests in the vast do main of theoretical physics. Josef Maria Jauch was born on 20 September 1914, the son of Josef Alois and Emma (nee Conti) Jauch, in Lucerne, Switzerland. Love of science was aroused in him early in his youth. At the age of twelve he came upon a popular book on astronomy, and an exam ple treated in this book mystified him. It was stated that if a planet travels around a centre of Newtonian attraction with a pe riod T, and if that planet were stopped and left to fall into the centre from any point of the circular orbit, it would arrive at the centre in the time T/I32. Young Josef puzzled about this for several months until he made his first scientific discovery : that this result could be derived from Kepler's third law in a quite elementary way.

Author: Lisa Randall
Publisher: HarperCollins
ISBN: 0062328514
Category : Science
Languages : en
Pages : 359

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In this brilliant exploration of our cosmic environment, the renowned particle physicist and New York Times bestselling author of Warped Passages and Knocking on Heaven’s Door uses her research into dark matter to illuminate the startling connections between the furthest reaches of space and life here on Earth. Sixty-six million years ago, an object the size of a city descended from space to crash into Earth, creating a devastating cataclysm that killed off the dinosaurs, along with three-quarters of the other species on the planet. What was its origin? In Dark Matter and the Dinosaurs, Lisa Randall proposes it was a comet that was dislodged from its orbit as the Solar System passed through a disk of dark matter embedded in the Milky Way. In a sense, it might have been dark matter that killed the dinosaurs. Working through the background and consequences of this proposal, Randall shares with us the latest findings—established and speculative—regarding the nature and role of dark matter and the origin of the Universe, our galaxy, our Solar System, and life, along with the process by which scientists explore new concepts. In Dark Matter and the Dinosaurs, Randall tells a breathtaking story that weaves together the cosmos’ history and our own, illuminating the deep relationships that are critical to our world and the astonishing beauty inherent in the most familiar things.