This Workshop was organized to bring once more tagether the scientists of the rather heterogeneaus field of exotic atoms. At present the main topic of the field seems to be the study of the atomic cascade. There are some who study it intentionally -Iet us call them cascadeurs -and others who think they investigate other features of the exotic atoms (like Coulomb capture, particle transfer, muon catalyzed fusion, chemical effects, fundamental properties, etc.) -users-while in fact they study some special consequences of the same atomic cascade. We decided to get cascadeurs and users discuss the problems of exotic atoms at wonderful Erice, at the 5th Course of the International School of Physics of Exotic Atoms. Our Workshop was quite successful, we have heard excellent talks from participants from a dozen countfies and most of them have prepared written contributions for this volume. The Organizers express their gratitude to all participants for their contributions, especially to David Measday for bis concluding remarks (not printed here) and to James Cohen for jumping in for Leonid Ponomarev who had to leave unexpectedly in the middle of the meeting. We greatly appreciate the enthusiastic help of Marianne Signer in every stage of the organization work. Am , of course, the Workshop could not happen at all without the incredibly efficient organization by the Ettore Majorana Centre of Scientific Culture. Leopold M. Simons Dezso Horvath Gabriele Torelli V CONTENTS OPENING ADDRESS . . . . . . . . . . . . . . . . . . . . . . . . . . xi . . . . . . ."

The NATO Advanced Research Workshop on Fundamental Aspects of Inert Gases in Solids, held at Bonas, France from 16-22 September 1990, was the fifth in a series of meetings that have been held in this topic area since 1979. The Consultants' Meeting in that year at Harwell on Rare Gas Behaviour in Metals and Ionic Solids was followed in 1982 by the Jiilich Inter national Symposium on Fundamental Aspects of Helium in Metals. Two smaller meetings have followed-a CECAM organised workshop on Helium Bubbles in Metals was held at Orsay, France in 1986 while in February 1989, a Topical Symposium on Noble Gases in Metals was held in Las Vegas as part of the large TMS/AIME Spring Meeting. As is well known, the dominating feature of inert gas atoms in most solids is their high heat of solution, leading in most situations to an essentially zero solubility and gas-atom precipita tion. In organising the workshop, one particular aim was to target the researchers in the field of inert-gas/solid interactions from three different areas--namely metals, tritides and nuclear fuels-in order to encourage and foster the cross-fertilisation of approaches and ideas. In these three material classes, the behaviour of inert gases in metals has probably been most studied, partly from technological considerations-the effects of helium production via (n, a) reac tions during neutron irradiation are of importance, particularly in a fusion reactor environ ment-and partly from a more fundamental viewpoint."

In the interest of speed and economy the notation of the orig inal text has been retained so that the cross product of two vectors A and B is denoted by [AB], the dot product by (AB), the Laplacian operator by ~. etc. It might also be worth pointing out that the temperature is frequently expressed in energy units in the Soviet literature so that the Boltzmann constant will be missing in various familiar expressions. In matters of terminology, whenever pos sible several forms are used when a term is first introduced, e. g. , magnetoacoustic and magnetosonic waves, "probkotron" and mirror machine, etc. It is hoped in this way to help the reader to relate the terms used here with those in existing translations and with the conventional nomenclature. In general the system of literature citation used in the bibliographies follows that of the American Institute of Physics "Soviet Physics" series. Except for the cor rection of some obvious misprints the text is that of the original. We wish to express our gratitude to Academician Leontovich for kindly providing the latest corrections and additions to the Russian text. v CONTENTS Steady-State Plasma Flow in a Magnetic Field A. I. Morozov and L. S. Solov'ev Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter 1. Acceleration Mechanisms , * * * * * * * * * * . 2 1. Microscopic Picture of Plasma Acceleration . . . . . . . . . . . . . . . . . . . 2 2.

The main goal of this book is to elucidate what kind of experiment must be performed in order to determine the full set of independent parameters which can be extracted and calculated from theory, where electrons, photons, atoms, ions, molecules, or molecular ions may serve as the interacting constituents of matter. The feasibility of such perfect' and-or `complete' experiments, providing the complete quantum mechanical knowledge of the process, is associated with the enormous potential of modern research techniques, both, in experiment and theory. It is even difficult to overestimate the role of theory in setting of the complete experiment, starting with the fact that an experiment can be complete only within a certain theoretical framework, and ending with the direct prescription of what, and in what conditions should be measured to make the experiment `complete'. The language of the related theory is the language of quantum mechanical amplitudes and their relative phases. This book captures the spirit of research in the direction of the complete experiment in atomic and molecular physics, considering some of the basic quantum processes: scattering, Auger decay and photo-ionization. It includes a description of the experimental methods used to realize, step by step, the complete experiment up to the level of the amplitudes and phases. The corresponding arsenal includes, beyond determining the total cross section, the observation of angle and spin resolved quantities, photon polarization and correlation parameters, measurements applying coincidence techniques, preparing initially polarized targets, and even more sophisticated methods. The `complete' experiment is, until today, hardly to perform. Therefore, much attention is paid to the results of state-of-the-art experiments providing detailed information on the process, and their comparison to the related theoretical approaches, just to mention relativistic multi-configurational Dirac-Fock, convergent close-coupling, Breit-Pauli R-matrix, or relativistic distorted wave approaches, as well as Green's operator methods. This book has been written in honor of Herbert Walther and his major contribution to the field but even to stimulate advanced Bachelor and Master students by demonstrating that obviously nowadays atomic and molecular scattering physics yields and gives a much exciting appreciation for further advancing the field.

This thesis presents the first measurements of jets in relativistic heavy ion collisions as reported by the ATLAS Collaboration. These include the first direct observation of jet quenching through the observation of a centrality-dependent dijet asymmetry. Also, a series of jet suppression measurements are presented, which provide quantitative constraints on theoretical models of jet quenching. These results follow a detailed introduction to heavy ion physics with emphasis on the phenomenon of jet quenching and a comprehensive description of the ATLAS detector and its capabilities with regard to performing these measurements.

The second edition of "The Chemistry of the Superheavy Elements" provides a complete coverage of the chemistry of a series of elements beginning with atomic number 104 - the transactinides or superheavy elements - including their nuclear properties and production in nuclear reactions at heavy-ion accelerators. The contributors to this work include many renowned scientists who, during the last decades, have made vast contributions towards understanding the physics and chemistry of these elusive elements, both experimentally and theoretically. The main emphasis here is on demonstrating the fascinating studies involved in probing the architecture of the Periodic Table at its uppermost end, where relativistic effects drastically influence chemical properties. All known chemical properties of these elements are described together with the experimental techniques applied to study these short-lived man-made elements one atom-at-a-time. The status of theoretical chemistry and of empirical models is presented as well as aspects of nuclear physics. In addition, one chapter outlines the meanderings in this field from a historical perspective and the search for superheavy elements in Nature.

While electromagnetic interactions were first used to probe the structure of elementary particles more than 20 years ago, their importance has only become fully evident in the last 10 years. In the resonance region, photo production experiments have provided clear evidence for simple quark model ideas, and confirmed the Melosh-transformed SU(6)w as a relevant symmetry classification. At higher energies, their most striking feature is their similarity to hadron-induced reactions, and they have provided fresh insight into the ideas developed to explain strong-interaction physics. New dimensions are added by taking the photon off mass shell, both in the spacelike region, where the development of high-energy electron and muon beams has led to the discovery and study of scaling and the intro duction of "partons," and even more dramatically in the timelike region, where the development of high-energy electron-positron storage rings has led to the exciting discoveries of the last four years. In view of the immense interest stimulated by these developments, an extensive review of our present state of knowledge is both timely and useful. Because of the very wide range of the subject, a cooperative venture presents itself as the most suitable format and is the one we have adopted here. The emphasis throughout is primarily, but not entirely, on phenomenology, concentrating on describing the main features of the experimental data and on the theoretical ideas used directly in their inter pretation."

My aim in this book has been to give an account of the theoretical methods of analysis of multiphoton processes in atomic physics. In this account I have emphasized systematic methods as opposed to ad hoc approaches. Both perturbative and nonperturbative methods are presented with il- lustrative results of concrete applications. The perturbation theory is the primary tool of analysis of nonresonant multiphoton processes. It is developed here in conjunction with a diagrammatic language and is also renormalized to free it from the unwanted divergences which accompany the ordinary treatment when higher-order corrections are considered. The nonperturbative methods (i.e., methods other than that of power series ex- pansion in the field strength) become particularly important for consistent treatments of problems involving, for example, intermediate resonances, high field strengths, and finite pulse duration. The specifically nonpertur- bative methods for multiphoton transitions are presented in Chapters 6-11. The methods of resolvent equations and of effective Hamiltonians are developed for both the stationary and the time-dependent fields. The densi- ty matrix method is presented in conjunction with the problems of relaxa- tion and of fluctuating fields. The Floquet theory is presented both in the energy domain and in the time domain. Also treated are the methods of continued fractions, recursive iterative equations, and chain Hamiltonians.

Recent years have seen the proliferation of new computer designs that employ parallel processing in one form or another in order to achieve maximum performance. Although the idea of improving the performance of computing machines by carrying out parts of the computation concurrently is not new (indeed, the concept was known to Babbage ), such machines have, until fairly recently, been confined to a few specialist research laboratories. Nowadays, parallel computers are commercially available and they are finding a wide range of applications in chemical calculations. The purpose of this volume is to review the impact that the advent of concurrent computation is already having, and is likely to have in the future, on chemical calculations. Although the potential of concurrent computation is still far from its full realization, it is already clear that it may turn out to be second in importance only to the introduction of the electronic digital computer itself.

The 1994 Cargese Summer Institute on Frontiers in Partide Physics was organized by the Universite Pierre et Marie Curie, Paris (M. Levy), the Ecole Normale Superieure, Paris (J. Iliopoulos), the Katholieke Universiteit Leuven (R. Gastmans), and the Uni- versite Catholique de Louvain (J. -M. Gerard), which, since 1975, have joined their efforts and worked in common. It was the eleventh Summer Institute on High Energy Physics organized jointly at Cargese by three of these universities. Severa! new frontiers in partide physics were thoroughly discussed at this school. the new euergy range in deep-iuelastic electron-proton scattering is beiug In particular, explored by HERA (DESY, Hamburg), and Professor A. De Roeck described the first results from the H1 and Zeus experiments, while Professors A. H. Mueller aud Z. Kuuszt discussed their relevance from the theoretical point of view. Also, the satellite exper- iments offer new possibilities for exploring the links between astrophysics, cosmology, and partide physics. A critica] a. nalysis of these experiments was performed by Pro- fessor B. Sadoulet, and Professor M. Spiro made the connection with the results from earth-based neutrino experiments. Finally, much attentiou was giveu to the latest re- sults from the TEVATRON (Fermilab, USA), showing further evidence for the loug awaited top quark. Professor A. Tollestrup gave a detailed presentation of these results aud discussed their importance for the Standard Model.

The series Advances in the Physics of Particles and Nuclei (APPN) is devoted to the archiving, in printed high-quality book format, of the comprehensive, long shelf-life reviews published in The European Physical Journal A and C. APPN will be of benefit in particular to those librarians and research groups, who have chosen to have only electronic access to these journals. Occasionally, original material in review format and refereed by the series' editorial board will also be
included.

This volume contains the following two reviews:
Nora Brambilla et al.: Heavy Quarkonium: Progress, Puzzles and Opportunities Daniel Wicke: Properties of the Top Quark

At extremely low temperatures, clouds of bosonic atoms form what is known as a Bose-Einstein condensate. Recently, it has become clear that many different types of condensates -- so called fragmented condensates -- exist. In order to tell whether fragmentation occurs or not, it is necessary to solve the full many-body Schrodinger equation, a task that remained elusive for experimentally relevant conditions for many years. In this thesis the first numerically exact solutions of the time-dependent many-body Schrodinger equation for a bosonic Josephson junction are provided and compared to the approximate Gross-Pitaevskii and Bose-Hubbard theories. It is thereby shown that the dynamics of Bose-Einstein condensates is far more intricate than one would anticipate based on these approximations. A special conceptual innovation in this thesis are optimal lattice models. It is shown how all quantum lattice models of condensed matter physics that are based on Wannier functions, e.g. the Bose/Fermi Hubbard model, can be optimized variationally. This leads to exciting new physics."

The manuscript tackles one of the most interesting branches of plasma phys ics, the electrodynamics of the plasma. 99% of matter in the universe occur in the plasma state, - e. g., stars, gaseous nebulae, interstellar gas. The plasma also widely occurs on earth. Thus, the ionosphere protects human beings from the destroying effects of the solar radiation and provides the long distance radio communication. Plasmas also show up in metals and semicon ductors, and it is difficult to overestimate their importance in our everyday life. But even more important is that the power engineering of the future is connected with plasmas since the plasma is the fuel for thermonuclear reca tions and a practically unlimited source of energy harmless to the environ ment. For the description of a hot plasma a unique logically complete and consistent theoretical model has been developed on the basis of the Maxwell Vlasov equations. We tried to carry this idea through the entire text, which aims to present an orderly exposition of electromagnetic properties of the plasma within the Maxwell-Vlasov model. Both linear and nonlinear elec trodynamics of the plasma are presented. The first part (Chap. 1-5) deals with the linear electromagnetic properties of the plasma in thermodynamic equilibrium. The basic equations of the Maxwell-Vlasov model are introduced and the properties of the plasma in equilibrium are studied in the linear approximation of the electromagnetic field. The second part (Chaps."

The volume consists of up-to-date reviews and a selection of contributed papers on subjects including the structure and physical properties of molecular clouds, their role in the star formation process, their dust and chemical properties, molecular cloud surveys of the Milky Way, cloud evolution, problems in cloud mass determinations (a panel discussion and review), the CO properties of external galaxies, nuclei of galaxies as revealed by molecular observations, and galactic spiral structure as reflected by molecular cloud distributions. The abstracts of poster papers on these topics presented at the conference are also included. This book is both a valuable reference and a compendium of current knowledge in this field. It should be of special interest to all students and researchers who work on the physics of star formation, the interstellar medium, molecular clouds and galactic structure.

These lectures review the recently developed vector coherent state method. The book is an excellent introduction to the field because of the many examples treated in detail, in particular those from nuclear and particle physics. These calculations will be welcomed by researchers and graduate students. The author reviews the concepts of coherent states of the Heisenberg algebra and shows then that the vector coherent state method maps the higher symmetry algebra into an n-dimensional harmonic oscillator algebra coupled with a simple intrinsic symmetry algebra. The formulation involves some vector (or analogous higher symmetry) coupling of the intrinsic algebra with the n-dimensional oscillator algebra, leading to matrix representations and Wigner coefficients of the higher symmetry algebra expressed in terms of simple calculable functions and recoupling coefficients for the simpler intrinsic algebra.