Elementary particle physics is the quadrant of nature whose laws can be written in a few lines with absolute precision and the greatest empirical adequacy. The lectures presented in this book introduce students and interested readers to the entire subject in a compact way. It details the current theory of ElectroWeak interactions after one year of operation of the Large Hadron Collider at CERN in Geneva, focusing on open questions that the experiments might allow to answer.
This book is based on the lecture course taught by the author for about three decades at Charles University. The author gives a thorough and easy-to-read account of the basic principles of the standard model of electroweak interactions, describes various theories of electromagnetic and weak interactions, and explains the gauge theory of electroweak interactions. The criterion of the tree-level unitarity is used throughout the text to check the gradual steps leading to the renormalizable electroweak theory. Five appendices expound on some special techniques of the Standard Model, used in the main body of the text.The book can be read with just a preliminary knowledge of quantum field theory. In comparison with the first edition of the book published more than 20 years ago, new passages concerning the Higgs boson are added, as well as some new problems and solutions.
This book offers a self-contained introduction to the theory of electroweak interactions based on the semi-classical approach to relativistic quantum field theory, with thorough discussion of key aspects of the field. The basic tools for the calculation of cross sections and decay rates in the context of relativistic quantum field theory are reviewed in a short, but complete and rigorous, presentation. Special attention is focused on relativistic scattering theory and on calculation of amplitude in the semi-classical approximation. The central part of the book is devoted to an illustration of the unified field theory of electromagnetic and weak interactions as a quantum field theory with spontaneously broken gauge invariance; particular emphasis is placed on experimental confirmations of the theory. The closing chapters address the most recent developments in electroweak phenomenology and provide an introduction to the theory and phenomenology of neutrino oscillations. In this 2nd edition the discussion of relativistic scattering processes in the semi-classical approximation has been revised and as a result intermediate results are now explicitly proven. Furthermore, the recent discovery of the Higgs boson is now taken into account throughout the book. In particular, the Higgs decay channel into a pair of photons, which has played a crucial role in the discovery, is discussed. As in the first edition, the accent is still on the semi-classical approximation. However, in view of the necessity of a discussion of H !, the authors give several indications about corrections to the semiclassical approximation. Violation of unitarity is discussed in more detail, including the dispersion relations as a tool for computing loop corrections; the above-mentioned Higgs decay channel is illustrated by means of a full one-loop calculation; and finally, loop effects on the production of unstable particles (such as the Z0 boson) are now discussed. Finally, the neutrino mass and oscillation analysis is updated taking into account the major achievements of the last years.
The week-long Lake Louise Winter Institute starts with three days of pedagogical lectures by invited speakers, and the remainder of the time is for short presentations on current research topics. This year, the theme of the Institute was 'Topics in Electroweak Physics'. The invited lecturers were Drs E G Adelberger, G Altarelli, J Ellis, J-M Poutissou, B Sadoulet and S Wojcicki.
This book comprises the lectures of a two-semester course on quantum field theory, presented in a quite informal and personal manner. The course starts with relativistic one-particle systems, and develops the basics of quantum field theory with an analysis on the representations of the Poincaré group. Canonical quantization is carried out for scalar, fermion, Abelian and non-Abelian gauge theories. Covariant quantization of gauge theories is also carried out with a detailed description of the BRST symmetry. The Higgs phenomenon and the standard model of electroweak interactions are also developed systematically. Regularization and (BPHZ) renormalization of field theories as well as gauge theories are discussed in detail, leading to a derivation of the renormalization group equation. In addition, two chapters — one on the Dirac quantization of constrained systems and another on discrete symmetries — are included for completeness, although these are not covered in the two-semester course.This second edition includes two new chapters, one on Nielsen identities and the other on basics of global supersymmetry. It also includes two appendices, one on fermions in arbitrary dimensions and the other on gauge invariant potentials and the Fock-Schwinger gauge.
Gauge Theory of Weak Interactions treats the unification of electromagnetic and weak interactions and considers related phenomena. First, the Fermi theory of beta decay is presented, followed by a discussion of parity violation, clarifying the importance of symmetries. Then the concept of a spontaneously broken gauge theory is introduced, and all necessary mathematical tools are carefully developed. The "standard model" of unified electroweak interactions is thoroughly discussed including current developments. The final chapter contains an introduction to unified theories of strong and electroweak interactions. Numerous solved examples and problems make this volume uniquely suited as a text for an advanced course. Thisfourth edition has been carefully revised.
Supernovae explosion, combustion of solar hydrogen to form helium, heavy quark decay, or nuclear beta radiation, all weak interaction phenomena, are not unrelated to electromagnetism, but closely linked to it through the Higgs field. This ebook contains a modern introduction to the electroweak unification theory, as part of the so called Standard Model of particle physics. Not only some of the key theoretical ideas are exposed in a precise way, but also the experiments that revealed them. The main highlights of the theory consolidation process are examined which, concerning its experimental counterpart, span over 40 years, from the discovery of neutral currents in1973 to the Higgs boson in 2012. The reader is assumed to have been introduced to Quantum Mechanics and theories based on the gauge invariance principle, and to be familiar with Dirac’s theory for the relativistic electron. The course is specially suited for undergraduate students in physics, as part of an optional subject of elementary particles. The course consists in nine lectures, that on the blackboard take about 90 minutes each. It contains a very select collection of problems and exercises, having as a connecting thread the calculation of the lifetime of elementary fermions and bosons, as well as the comprehension of some experimental results of historical relevance.