Quantum field theory

About: Quantum field theory is a research topic. Over the lifetime, 24682 publications have been published within this topic receiving 749928 citations. The topic is also known as: QFT.

Quantum Field Theory

Abstract: This book is a modern pedagogic introduction to the ideas and techniques of quantum field theory. After a brief overview of particle physics and a survey of relativistic wave equations and Lagrangian methods, the quantum theory of scalar and spinor fields, and then of gauge fields, is developed. The emphasis throughout is on functional methods, which have played a large part in modern field theory. The book concludes with a brief survey of 'topological' objects in field theory and, new to this edition, a chapter devoted to supersymmetry.

CP Violation in the Renormalizable Theory of Weak Interaction

Abstract: In a framework of the renormalizable theory of weak interaction, problems of CP-violation are studied. It is concluded that no realistic models of CP-violation exist in the quartet scheme without introducing any other new fields. Some possible models of CP-violation are also discussed. When we apply the renormalizable theory of weak interaction1l to the hadron system, we have some limitations on the hadron model. It is well known that there exists, in the case of the triplet model, a difficulty of the strangeness chang­ ing neutral current and that the quartet model is free from this difficulty. Fur­ thermore, Maki and one of the present authors (T.M.) have shown2l that, in the latter case, the strong interaction must be chiral SU ( 4) X SU ( 4) invariant as precisely as the conservation of the third component of the iso-spin 13 • In addi­ tion to these arguments, for the theory to be realistic, CP-violating interactions should be incorporated in a gauge invariant way. This requirement will impose further limitations on the hadron model and the CP-violating interaction itself. The purpose of the present paper is to investigate this problem. In the following, it will be shown that in the case of the above-mentioned quartet model, we cannot make a CP-violating interaction without introducing any other new fields when we require the following conditions: a) The mass of the fourth member of the quartet, which we will call (, is sufficiently large, b) the model should be con­ sistent with our well-established knowledge of the semi-leptonic processes. After that some possible ways of bringing CP-violation into the theory will be discussed. We consider the quartet model with a charge assignment of Q, Q -1, Q -1 and Q for p, n, A. and (, respectively, and we take the same underlying gauge group SUweak (2) X SU(1) and the scalar doublet field cp as those of Weinberg's original model.1l Then, hadronic parts of the Lagrangian can be devided in the following way:

The quantum theory of fields

Abstract: In this third volume of The Quantum Theory of Fields, available for the first time in paperback, Nobel Laureate Steven Weinberg continues his masterly exposition of quantum field theory. This volume presents a self-contained, up-to-date and comprehensive introduction to supersymmetry, a highly active area of theoretical physics. The text introduces and explains a broad range of topics, including supersymmetric algebras, supersymmetric field theories, extended supersymmetry, supergraphs, non-perturbative results, theories of supersymmetry in higher dimensions, and supergravity. A thorough review is given of the phenomenological implications of supersymmetry, including theories of both gauge and gravitationally-mediated supersymmetry breaking. Also provided is an introduction to mathematical techniques, based on holomorphy and duality, that have proved so fruitful in recent developments. This book contains much material not found in other books on supersymmetry, including previously unpublished results. Exercises are included.

An Introduction to Quantum Field Theory

Abstract: Feynman Diagrams and Quantum Electrodynamics * Invitation: Pair Production in e+e- Annihilation * The Klein-Gordon Field * The Dirac Field * Interacting Fields and Feynman Diagrams * Elementary Processes of Quantum Electrodynamics * Radiative Corrections: Introduction * Radiative Corrections: Some Formal Developments * Final Project: Radiation of Gluon Jets Renormalization * Invitation: Ultraviolet Cutoffs and Critical Fluctuations * Functional Methods * Systematics of Renormalization * Renormalization and Symmetry * The Renormalization Group * Critical Exponents and Scalar Field Theory * Final Project: The Coleman-Weinberg Potential Non-Albelian Gauge Theory * Invitation: The Parton Model of Hadron Structure * Non-Albein Gauge Invariance * Quantization of Non-Abelian Gauge Theories * Quantum Chromodynamics * Operator Products and Effective Vertices * Perturbation Theory Anomalies * Gauge Theories with Spontaneous Symmetry Breaking * Quantization of Spontaneously Broken Gauge Theories * Final Project: Decays of the Higgs Boson * Epilogue: Field Theory at the Frontier

A planar diagram theory for strong interactions

Abstract: A gauge theory with colour gauge group U( N ) and quarks having a colour index running from one to N is considered in the limit N → ∞, g 2 N fixed. It is shown that only planar diagrams with the quarks at the edges dominate; the topological structure of the perturbation series in 1/ N is identical to that of the dual models, such that the number 1/ N corresponds to the dual coupling constant. For hadrons N is probably equal to three. A mathematical framework is proposed to link these concepts of planar diagrams with the functional integrals of Gervais, Sakita and Mandelstam for the dual string.