Preface
The aim of the Summer Course on “Selected topics of nonperturbative QCD” was to gather together experts and have an exhaustive discussion on those aspects of QCD which are related to its underlying structure as a field theory, and to its mechanisms.
Perturbative expansions do not work at large distances for QCD: the hadron spectrum, the confinement of colour, its deconfinement at high temperatures and the breaking of chiral symmetry all need nonperturbative methods of analysis. Sum rules, chiral perturbation theory and the formulation of QCD on a lattice are some of the tools used to test models, like the stochastic vacuum, the instanton liquid or the condensation of monopoles in the vacuum to produce dual superconductivity and confinement.
These subjects have been covered by the lecturers of this course, from different points of view, but on the average with more emphasis on the understanding of mechanisms, rather than on a direct and quantitative comparison with experiment. A critical comparison then emerges between the different approaches. This book can be considered as a good reference text, in some sense unique, in that it collects and allows the comparison of different ideas usually presented sparsely scattered between more phenomenological topics.
The Editors