These proceedings consist of a series of detailed pedagogical lectures on a variety of theoretical and experimental topics. Together they comprise a comprehensive survey of current approaches to the physics of the standard model. The school is slanted to emphasize dynamics, recent theoretical advances, and new experiments.

An introduction to symmetry breaking in the standard model / Edward Farhi -- Physics beyond the standard model / Jonathan A. Bagger -- Chiral effective Lagrangians / Heinrich Leutwyler -- Towards semi-classical string theory / Jeffrey A. Harvey -- Renormalization of electroweak gauge interactions / Dallas C. Kennedy -- Electroweak experiments at LEP / Alain Blondel -- The CKM matrix and CP violation / Yosef Nir -- Axion searches / Pierre Sikivie -- Lattice QCD / Andreas S. Kronfeld -- Introduction to perturbative QCD / George Sterman -- Heavy quark effective field theory / Howard Georgi -- Heavy flavor physics on the lattice / Estia Eichten -- Two lectures on neutrinos / Pierre Ramond

The twentieth Johns Hopkins Workshop on current problems in particle theory took place in Heidelberg. The topic of the workshop was chosen in view of the phantastic success enjoyed by the standard model of electroweak and strong interactions.Until today, no significant deviations from the predictions of the standard model have been observed. However, precision tests have been dominantly performed in the high-energy domain, where the QCD coupling constant is small enough to allow for a perturbative treatment of the strong interaction. It is therefore very important to consider also the low-energy region for which non-perturbative aspects of QCD come into play.

This book is a unique report on the frontiers of subnuclear physics presented by world specialists in a clear, rigorous and simple way.The problem of the physical vacuum is presented in the opening lecture by T D Lee and the effective string-theoretical approach to cosmological vacua by G Veneziano. Effective theoretical approaches to light and heavy quark physics are presented by H Leutwyler and M Neubert. V N Gribov discusses the quark confinement and N Seiberg the problem of finding the effective actions in supersymmetric theories. A detailed analysis confronting electroweak theory with the high precision experimental data is presented by D Schildknecht. The great specialist in membrane theory, M Duff, presents the latest results of the 11-dimensional approach, while the finite temperature effective theories are discussed by M Shaposhnikov. The unification and the physics beyond the standard model constitute the content of the lectures by R Barbieri and D Nanopoulos. The experimental data from LEP and Hera are presented by M Pohl and G Wolf. N F Ramsey, the world specialist in the field, discusses how to explore the universe with atomic clocks. An elusive Z' is the subject of a specialised seminar by P Frampton.This volume contains the reports presented by a selected group of “new talents” on various topics in the field of subnuclear physics.

This volume contains the proceedings of one of the first schools devoted to effective field theories. This subject has recently raised great interest in high energy physics and has become extremely useful in the analysis of experimental data. The lectures cover a wide spectrum of applications of effective field theories with a pedagogical approach, also paying attention to the most recent developments.

This PhD thesis is dedicated to a subfield of elementary particle physics called “Flavour Physics”. The Standard Model of Particle Physics (SM) has been confirmed by thousands of experimental measurements with a high precision. But the SM leaves important questions open, like what is the nature of dark matter or what is the origin of the matter-antimatter asymmetry in the Universe. By comparing high precision Standard Model calculations with extremely precise measurements, one can find the first glimpses of the physics beyond the SM – currently we see the first hints of a potential breakdown of the SM in flavour observables. This can then be compared with purely theoretical considerations about new physics models, known as model building. Both precision calculations and model building are extremely specialised fields and this outstanding thesis contributes significantly to both topics within the field of Flavour Physics and sheds new light on the observed anomalies.

In this volume, precision tests of the Standard Model and a wide spectrum of physics beyond it, such as supersymmetry, grand unification and the fermion mass problem, are covered. The emphasis is on the areas where new experimental results will lead to significant progress: neutrino physics, CP violation and B physics. The articles written by top level experts in the fields, give a comprehensive view of the state-of-the-art of modern particle physics.