Unification And Supersymmetry

The theoretical understanding of elementary particle interactions has under gone a revolutionary change during the past one and a half decades. The spontaneously broken gauge theories, which in the 1970s emerged as a prime candidate for the description of electro-weak (as weIl as strong) interactions, have been confirmed by the discovery of neutral weak currents as weIl as the w- and Z-bosons. We now have a field theory of electro-weak interactions at energy scales below 100 GeV-the Glashow-Weinberg-Salam theory. It is a renormalizable theory which enables us to do calculations without en countering unnecessary divergences. The burning question now is: Wh at lies ahead at the next level of unification? As we head into the era of supercolliders and ultrahigh energy machines to answer this question, many ap, pealing possi bilities exist: left-right symmetry, technicolor, compositeness, grand unifica ti on, supersymmetry, supergravity, Kaluza-Klein models, and most recently superstrings that even unify gravity along with other interactions. Experi ments will decide if any one or any combination of these is to be relevant in the description of physics at the higher energies. As an outcome of our con fidence in the possible scenerios for elementary particle physics, we have seen our understanding of the early uni verse improve significantly.

Derived from a course given at the University of Maryland for advanced graduate students, this book deals with some of the latest developments in our attempts to construct a unified theory of the fundamental interactions of nature. Among the topics covered are spontaneous symmetry breaking, grand unified theories, supersymmetry, and supergravity. the book starts with a quick review of elementary particle theory and continues with a discussion of composite quarks, leptons, Higgs bosons, and CP violation; it concludes with consideration of supersymmetric unification schemes, in which bosons and leptons are considered in some sense equivalent. The third edition will be completely revised and brought up to date, particularly by including discussions of the many experimental developments in recent years.

This book covers the present status of art of grand unification with and without supersymmetry (gravity), including cosmological consequences. It is addressed to graduate students and researchers interested in this fastly developing field. But without necessarily any previous experience, however, at least some parts of the book and, in particular, those concerning the most recent developments, are of interest to actively involved researchers in the field.

This book offers a comprehensive discussion of developments at the interface of particle physics, supergravity, and cosmology, for graduates and researchers.

These course-tested lectures provide a technical introduction to Supersymmetric Grand Unified Theories (SUSY GUTs), as well as a personal view on the topic by one of the pioneers in the field. While the Standard Model of Particle Physics is incredibly successful in describing the known universe it is, nevertheless, an incomplete theory with many free parameters and open issues. An elegant solution to all of these quandaries is the proposed theory of SUSY GUTs. In a GUT, quarks and leptons are related in a simple way by the unifying symmetry and their electric charges are quantized, further the relative strength of the strong, weak and electromagnetic forces are predicted. SUSY GUTs additionally provide a framework for understanding particle masses and offer candidates for dark matter. Finally, with the extension of SUSY GUTs to string theory, a quantum-mechanically consistent unification of the four known forces (including gravity) is obtained. The book is organized in three sections: the first section contains a brief introduction to the Standard Model, supersymmetry and the Minimal Supersymmetric Standard Model. Then SUSY GUTs in four space-time dimensions are introduced and reviewed. In addition, the cosmological issues concerning SUSY GUTs are discussed. Then the requirements for embedding a 4D SUSY GUT into higher-dimensional theories including gravity (i.e. String Theory) are investigated. Accordingly, section two of the course is devoted to discussing the so-called Orbifold GUTs and how in turn they solve some of the technical problems of 4D SUSY GUTs. Orbifold GUTs introduce a new set of open issues, which are then resolved in the third section in which it is shown how to embed Orbifold GUTs into the E(8) x E(8) Heterotic String in 10 space-time dimensions.

This book addresses the theoretical, phenomenological and experimental aspects of supersymmetry in particle physics as well as its implications in cosmology. Contents:SUSY and Higgs Searches: Experimental Results:Chargino and Neutralino Searches at LEP (C Hensel)Higgs Searches at LEP (S Andringa)R-Parity Violation Searches at LEP (R Barbier)Searches for Charged Higgs Bosons (M Ellert)SUSY, Higgs and GUT Phenomenology:SUSY Phenomenology at the EW and the GUT Scales (G Altarelli)Revealing SUSY at Colliders (H Baer)Neutralino Dark Matter (S Scopel)Linear Collider Signals of Anomaly Mediated Supersymmetry Breaking (S Roy)SUSY Theory and SUSY QFT:Low Energy Supersymmetry in Warped Brane Worlds (Z Lalak)Effective Field Theories on the Branes with Spontaneously Broken Supersymmetry (D Sorokin)Soft Supersymmetry Breaking from Coset Space Dimensional Reduction (P Manousselis & G Zoupanos)Interacting Noncommutative Lumps (C Sochichiu)and other papers Readership: Graduate students, academics and researchers in accelerator, high-energy and theoretical physics. Keywords:Supersymmetry;Particle Physics;Cosmology;SUSY;Higgs Searches;GUT Phenomenology;Neutralino Dark Matter;Warped Brane