The fourth course of the International School on Physics with Low Energy Antiprotons was held in Erice, Sicily, at the Ettore Majorana Centre for Scientific Culture from 25 to 31 January, 1990. The previous courses covered topics related to fundamental symmetries, light and heavy quark spectroscopy, and antiproton-nucleus interactions. The purpose of this school is to review theoretical and experimental aspects of low energy antiproton physics concerning the quark-gluon structure of hadrons and the dynamics of the. antiproton-nucleon interaction. Another important objective is the discussion of future directions of research with low-and medium-energy antiprotons in the context of future medium energy facilities at CERN and elsewhere. These proceedings contain both the tutorial lectures and the various contributions presented during the school by the participants. The proceedings have been organised in three sections. The first section is devoted to the theoretical lectures and contributions. The selection of the various subjects wants to emphasize the correlation between antiproton-nucleon physics and the underlying description in terms of quarks and gluons. The second section contains an overview about 35 years of experiments with antiprotons. It gives an introduction to the particle physics aspects of the field by outlining the historical development of experiment and theory, and by describing the motivation and the results of three recent LEAR experiments in more detail. The third section contains most of the contributions of the participants describing in more detail certain aspects of current or planned experiments at LEAR.

This volume of the International School of Physics Enrico Fermi is dedicated to Valerio Filippini. He devoted his life to physics. Valerio Filippini was born in Somma Lombardo (Milano) on December 8, 1958. He obtained the Master Degree in Physics at the University of Pavia in 1982, cum laude. After a working parenthesis at an industrial firm, he became Research Physicist of INFN, Sezione di Pavia, in 1988 and was promoted Senior Research Physicist in 1993. He participated to the experiments PS 179 (TOFRADUPP) and PS 201 (Obelix) at LEAR (CERN), FINUDA at LNF and ATHENA at AD (CERN). His outstanding scientific contributions were provided in the OBELIX and FINUDA experiments. Nobody could compete with Filippini in exploiting at best the daily-evoluting performances of the computing tools for the needs of the experiments, both for on-line and off-line purposes. The FINUDA experiment collected physics data immediately after the roll-in thanks to the reliability and simplicity of the on-line system designed and assembled by the physicist. However, he was not only a 'Clavier Physicist' but a complete Scientist: he also leaded the Pavia Group in designing and providing advanced detectors, and in developing mathematical methods for the analysis of the data. His scientific contributions are documented by about 90 publications on refereed international journals, about 100 contributions to International Conferences and Workshops, and 3 invited talks.

The proceedings of this important conference consist of plenary and invited papers published in hard copy and CD-ROM versions. The contributed oral and poster presentations are included in the CD-ROM version only.

The study of QCD in the confinement regime poses some of the most difficult problems of fundamental physics at present. The mechanism of confinement itself is not described formally, and it is hard to investigate the properties of the fundamental theory in the determination of the structures and interactions of hadronic systems. The strong coupling and the extreme non-linearity of the theory severely limit the applicability and the extension and generalization of models and methods. The area of particle/nuclear physics called Hadron Physics deals with the phenomena determined by the confinement regime of QCD.The International Workshop on Hadron Physics 98 aimed to provide a framework for the comparative evaluation of different approaches to the difficult problems of QCD, and gathered together experts who have been leading developments in hadronic physics in recent years. As a central feature of the workshop program, there were four sets of lectures: (1) “An Introduction to Effective Field Theory” (J F Donoghue); (2) “Non-perturbative QCD” (A Di Giacomo); (3) “Diffraction: Past, Present and Future” (E Predazzi); “QCD at High Temperature and Density” (T Hatsuda). These courses provided a pedagogical and updated account of the recent developments that gave support to the discussion of frontier research problems. The lecturers did very useful work in the review and description of important lines of research.The lectures are reproduced in this book, together with invited talks and contributed papers dealing with specific research problems, for the use and appreciation of a wider audience.

An introduction to QCD, covering recent developments as well as giving a historical overview of the subject. Emphasis is placed on the method of QCD spectral sum rules, with applications to hadronic systems. Suitable for graduate students and researchers in high-energy and nuclear physics, both theoretical and experimental.