The purpose of the workshop is to discuss recent developments in our understanding of the relationship between field theory and string theory, with a focus on the physics of strong interactions and QCD

The relation between hadronic physics and string theory has long been a subject of fascination. The success of early string-related approaches in explaining many properties of hadrons (e.g., linear Regge trajectories, low-$p_T$ hadronic reactions, the Ademollo-Veneziano-Weinberg mass relation, etc.) placed the string theory, for a period of time, at the forefront of the competition for the role of the theory of the strong interactions.

The advent of QCD, which combines concise basic principles and an enormous predictive power, determined the outcome of this competition -- the theory of strong interactions is a field theory. For hard processes, QCD is a flexible and well developed tool for the computations which utilise its central property -- asymptotic freedom. On the other hand, the low-energy, strongly interacting domain of QCD remains an extremely difficult subject for field theoretical approaches. The nature of confinement and of the rich hadron spectrum are questions to which QCD is believed to possess the answers, but it has long become apparent that such answers are not easy to get from QCD.

Very early studies of nonperturbative dynamics in QCD hinted at deep connections between the gauge and string theories. A notable example is the pioneering work of 't Hooft on the classification of Feynman graphs in the large-$N_c$ limit of QCD, also known as the planar limit. Another example is the ``flux-tube'' picture of quark confinement. However, since 1970's little progress has been made in further unveiling this deep connection.

Very recently, the situation has begun to change. The Maldacena conjecture, put forward in 1997, established an explicit link between gauge theories and string theories. Although Maldacena's original example does not exhibit confinement, very soon the gauge-string correspondence was extended to confining theories somewhat similar to Yang-Mills or QCD. From these studies it now seems that a large class of four-dimensional gauge theories are equivalent to a ten-dimensional string theory on various curved spaces. The stringy description of the theory is perturbative when the gauge coupling g is small but the 't Hooft coupling g^2 N_c/4 pi is large. This is close to the region where much of non-perturbative QCD takes place. In the spirit of duality, string theory provides a new analytically controllable technique for approaching the domain which is extremely difficult to study from the field theory point of view.

While physical QCD itself cannot be directly investigated using current string theoretic methods, which at present require the 't Hooft coupling to be large at all energy scales, new insights into old problems of QCD are already being obtained. The list of problems include confinement, hadron spectra, the Froissart-Martin bound, thermodynamics and hydrodynamics of hot matter, and the deconfining phase transition. Phenomena previously thought to preclude any string-theory explanation, e.g., the power-law scaling behavior of hadronic cross sections and the partonic behavior of deep inelastic scattering, have received new interpretation from the string perspective. Some well-known regularities of hadron interactions, such as the vector meson dominance, seem to be natural from the point of view of string theory.

We believe now is the ideal time for a meeting aimed to enhance communication between the QCD and string-theory communities and to accelerate the development of new methodology for QCD based on the recent technical and conceptual advances in string theory. QCD physicists need to understand the framework of the string-based techniques, and string theorists need to learn how their efforts would be potentially of most value to QCD theorists. The communities need to work together in order that the power and the limitation of these new approaches can become clearer, and that maximum possible progress in solving QCD can be achieved.