This volume contains the lectures and contributions presented at the NATO Advanced Study Institute (ASI) on "Frontier Topics in Nuclear Physics", held at Predeal in Romania from 24 August to 4 September 1993. The ASI stands in a row of 23 Predeal Summer Schools organized by the Institute of Atomic Physics (Bucharest) in Predeal or Poiana-Brasov during the last 25 years. The main topics of the ASI were cluster radioactivity, fission and fusion. the production of very heavy elements, nuclear structure described with microscopic and collective models, weak: interaction and double beta decay, nuclear astrophysics, and heavy ion reactions from low to ultrarelativistic energies. The content of this book is ordered according to these topics. The ASI started with a lecture by Professor Greiner on the "Present and future of nuclear physics", showing the most important new directions of research and the interdisciplinary relations of nuclear physics with other fields of physics. This lecture is printed in the first chapter of the book.

This is the forth volume in a series of Lecture Notes based on the highly successful Euro Summer School on Exotic Beams.

The aim of these notes is to provide a thorough introduction to radioactive ion-beam physics at the level of graduate students and young postdocs starting out in the field.

Each volume covers a range of topics from nuclear theory to experiment and applications. Vol I has been published as LNP 651, Vol II has been published as LNP 700, and Vol. III has been published as LNP 764.

The study of the vibrations of polyatomic molecules has recently turned into one of the most widespread and powerful methods of studying molecular structure. These vibrations ap pear directly in the infrared absorption spectra and Raman spectra of gases, liquids, and solids. A measurement of the number of bands in addition to their positions (frequencies or wavelengths) offers the possibility of obtaining a great deal of important information regarding the geometric and mechanical properties of the molecules, the types of chemical bonds, and so forth. It is now quite difficult to list the vast number of specific problems solved by measuring vibrational fre quencies. As a result of the successful development of research methods and the widespread applica tion of vibrational spectra in analyzing the structures of molecules and the constitution of ma terials, it now becomes necessary to develop the theory of molecular vibrations further. Existing theory, of course, is based on the assumption of the harmonicity of molecular vi brations, which, strictly speaking, is not justified experimentally. The anharmonicity of the molecular vibrations has therefore to be taken into account by introducing appropriate approxi mations. Thus, in carrying out calculations on the vibrations of polyatomic molecules, one uses the force constants calculated from the observed frequency values. However, as a result of the anharmonicity of the vibrations, the values of the observed frequencies differ from the harmonic values, and the force constants used therefore differ from the true ones, i. e.

Modern nuclear physics is a well developed branch of physical science, with wide-ranging applications of its results in engineering and industry. At the same time, the development of a consistent theory of nuclei and nuclear processes presents certain problems. It is well known that the most important aim of nuclear physics is the study of nuclear structure and the explanation of properties on the basis of the interaction between nucleons which constitute nuclei. Difficulties of a modern theory of the nucleus are caused by both an insufficient knowledge of nuclear interactions and the multi particle character of nuclear systems. Experimental data on nuclear interactions do not contradict the hypothesis of the pair character of nuclear forces. However, the absence of rigorous meth ods of calculations of many particle nuclear systems with strong interaction makes it necessary to use macroscopic nuclear models to describe particular nuclear properties. Nuclear models have been developed in different ways, and the models themselves have been modified and complicated. In spite of the visible discrepancy, different models of the nucleus significantly supple ment one another. The development of nuclear models has led to considerable progress in the understanding of atomic nuclei. The current results of theo retical nuclear physics are reported in numerous scientific papers. The most important and relevant experimental and theoretical results can be found in many monographs, the best of which are written by well-known experts in the field."

In its combination of an advanced teaching standpoint with an emphasis on new perspectives and recent advances in the study of liquids formed by simple molecules, Molecular Liquids: New Perspectives in Physics and Chemistry provides a clear, understandable guide through the complexities of the subject. A wide range of topics is covered in the areas of intermolecular forces, statistical mechanics, the microscopic dynamics of simple liquids, thermodynamics of solutions, nonequilibrium molecular dynamics, molecular models for transport and relaxation in fluids, liquid simulations, statistical band shape theories, conformational studies, fast-exchange dynamics, and hydrogen bonding. The experimental techniques covered include: neutron scattering, X-ray diffraction, IR, Raman, NMR, quasielastic neutron scattering, and high-precision, time-resolved coherent Raman spectroscopy.

Dissociative Recombination of Molecular Ions with Electrons is a comprehensive collection of refereed papers describing the latest developments in dissociative recombination research. The papers are written by the leading researchers in the field. The topics covered include the use of microwave afterglows, merged beams and storage rings to measure rate coefficients and to identify the products and their yields. The molecules studied range in size from the smallest, H2+, to bovine insulin ions. The theoretical papers cover the important role of Rydberg states and the use of wave packets and quantum defect theory to deduce cross sections, rate constants and quantum yields. Several theoretical and experimental papers address the controversial topic of H3+ dissociative recombination and its importance in the interstellar medium. Dissociative recombination studies of other molecular ions in the interstellar medium and in cometary and planetary atmospheres are covered. Ionization is an important competitive process to dissociative recombination and its competition with predissociation and its role in the reverse process of the association of neutral species is presented. Dissociative attachment, in which an electron attaches to a neutral molecule, has many similarities to dissociative recombination. The topics covered include the accurate calculation of electron affinities, attachment to molecules, clusters, and to species absorbed on solid surfaces and electron scattering by a molecular anion.

Collision-or interaction-induced spectroscopy refers to radiative transitions, which are forbidden in free atoms or molecules, but which occur in clusters of interacting atoms or molecules. The most common phenomena are induced absorption, in the infrared region, and induced light scattering, which involves inelastic scattering of visible laser light. The particle interactions giving rise to the necessary induced dipole moments and polarizabilities are modelled at long range by multipole expansions; at short range, electron overlap and exchange mechanisms come into play. Information on atomic and molecular interactions and dynamics in dense media on a picosecond timescale may be drawn from the spectra. Collision-induced absorption in the infrared was discovered at the University of Toronto in 1949 by Crawford, Welsh and Locke who studied liquid O and N. Through the 1950s and 1960s, 2 2 experimental elucidation of the phenomenon, particularly in gases, continued and theoretical underpinnings were established. In the late 1960s, the related phenomenon of collision-induced light scattering was first observed in compressed inert gases. In 1978, an 'Enrico Fermi' Summer School was held at Varenna, Italy, under the directorship of J. Van Kranendonk. The lectures, there, reviewed activity from the previous two decades, during which the approach to the subject had not changed greatly. In 1983, a highly successful NATO Advanced Research Workshop was held at Bonas, France, under the directorship of G. Birnbaum. An important outcome of that meeting was the demonstration of the maturity and sophistication of current experimental and theoretical techniques.

Recent results from high-energy scattering and theoretical developments of string theory require a change in our understanding of the basic structure of space-time. This book is about the advancement of ideas on the stochastic nature of space-time from the 1930s onward. In particular, the author promotes the concept of space as a set of hazy lumps, first introduced by Karl Menger, and constructs a novel framework for statistical behaviour at the microlevel. The various chapters address topics such as space-time fluctuation and random potential, non-local fields, and the origin of stochasticity. Implications in astro-particle physics and cosmology are also explored. Audience: This volume will be of interest to physicists, chemists and mathematicians involved in particle physics, astrophysics and cosmology.

Paul Harteck Rensselaer Polytechnic Institute Troy, New York When the Maser and the Laser Were discovered, people were speculating if this was the beginning of a new page, or even a new chapter, in the Book of Physics. The Second Workshop on "Laser Interaction and Related Plasma Phenomena" held in Hartford made it clear that the perspective had changed, that people now question if the consequences of these discoveries constitute a new chapter, or possibly a new era in Physics. While the papers presented were all stimulating and of out standing quality, of special interest were the experiments which demonstrated that triggering of thermonuclear fusion by Laser techniques is indeed in the realm of the possible. Along these lines, I enjoy recalling an anecdote concerning the late F. G. Houtermans. I think that all who knew him will agree that he was an unusual genius and at the same time a very amusing colleague.

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 . . . . . . ."

Electroweak Phase Transition and the Early Universe, a NATO Advanced Re- search Workshop, was held March 23-25, 1994, at the Hotel Tivoli in Sintra, Portugal. The meeting was co-sponsored by three other Lisbon-based institutions: the Fundac;ao Gulbenkian, J. N.!. C. T. (Junta Nacional para Investigac;ao Cientifica e Tecnologica) and G. T. A. E. (Grupo Teorico de Alta Energias). The workshop brought together a large number of theoretical physicists who are actively researching topics relevant to the understanding of the standard model of electroweak interactions in the early universe. We were pleased and overwhelmed by the positive, and sometimes instan- taneous response that our enterprise raised right from its inception. The old town of Sintra provided a serene and pleasant environment for the par- ticipants. Some heated and controversial discussions on many unanswered questions in the standard model took place throughout the three days of the workshop. If one consensus emerged from the meeting, it was the imperative need for non-perturbative techniques for the understanding of the electroweak phase transition.

Nowadays the realm of intermediate energy as a bridge between nuclear and particle physics attracts considerable interest. This volume surveys recent developments in the theory of quark correlations in hadronic matter and also informs about experimental findings. The main themes are: dynamicalsymmetries of heavy quarks, diquarks, weak interactions, hadron spectroscopyand quark models, chiral invariant quark forces, quark confinement and quarkaspects of hadronic interactions.

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."

Electron magnetic resonance spectroscopy is undergoing something akin to a renaissance that is attributable to advances in microwave circuitry and signal processing software. EPR: Instrumental Methods is a textbook that brings the reader up to date on these advances and their role in providing better experimental techniques for biological magnetic resonance. Chapters in this book guide the reader from basic principles of spectrometer design through the advanced methods that are providing new vistas in disciplines such as oximetry, imaging, and structural biology. Key Features: Spectrometer design, particularly at low frequencies (below X-band), Design of spectrometer components unique to ENDOR and ESEEM, Optimization of EMR spectrometer sensitivity spanning many octaves, Algorithmic approach to spectral parameterization, Application of Fourier Methods to polymer conformation, oximetry, and imaging.

With the appearance of Volume 3 of our series the review articles them selves can speak for the nature of the series. Our initial aim of charting the field of nuclear physics with some regularity and completeness is, hopefully, beginning to be established. We are greatly indebted to the willing coopera tion of many authors which has kept the series on schedule. By means of the "stream" technique on which our series is based - in which articles emerge from a flow of future articles at the convenience of the authors-the articles appear in this volume without any special coordination of topics. The topics range from the interaction of pions with nuclei to direct reactions in deformed nuclei. There is a great number of additional topics which the series hopes to include. Some of these are indicated by our list of future articles. Some have so far not appeared on our list because the topics have been reviewed re cently in other channels. Much of our series has originated from the sug gestions of our colleagues. We continue to welcome such aid and we continue to need, particularly, more suggestions about experimentalists who might write articles on experimental topics."

vii FOREWORD TO THE ENGLISH EDITION The lectures which I gave at the University of Chicago ix It is an unusual pleasure to present Professor Heisen- in the spring of 1929 afforded me the opportunity of re- berg's Chicago lectures on "The Physical Principles of viewing the fundamental principles of quantum theory. the Quantum Theory" to a wider audience than could Since the conclusive studies of Bohr in 1927 there have attend them when they were originally delivered. Pro- been no essential changes in these principles, and many fessor Heisenberg's leading place in the development of new experiments have confirmed important consequences the new quantum mechanics is well recognized by those of the theory (for example, the Raman effect). But even who have been following its growth. It was in fact he who today the physicist more often has a kind of faith in the first saw clearly that in the older forms of quantum theory we were describing our spectra in terms of atomic mecha- correctness of the new principles than a clear understa- nisms regarding which we could gain no definite knowl- ing of them. For this reason the publication of these C- cago lectures in the form of a small book seems justified. edge, anq who first found a way to interpret (or at least describe) spectroscopic phenomena without assuming Since the formal mathematical apparatus of the quan- the existence of such atomic mechanisms.

The Seventh International Symposium on Gaseous Dielectrics was held in Knoxville, Tennessee, U. S. A. , on April 24-28, 1994. The symposium continued the interdisciplinary character and comprehensive approach of the preceding six symposia. Gaseous DielecIries VII is a detailed record of the symposium proceedings. It covers recent advances and developments in a wide range of basic, applied and industrial areas of gaseous dielectrics. It is hoped that Gaseous DielecIries VII will aid future research and development in, and encourage wider industrial use of, gaseous dielectrics. The Organizing Committee of the Seventh International Symposium on Gaseous Dielectrics consisted of G. Addis (U. S. A. ), L. G. Christophorou (U. S. A. ), F. Y. Chu (Canada), A. H. Cookson (U. S. A. ), O. Farish (U. K. ), I. Gallimberti (Italy) , A. Garscadden (U. S. A. ), D. R. James (U. S. A. ), E. Marode (France), T. Nitta (Japan), W. Pfeiffer (Germany), Y. Qiu (China), I. Sauers (U. S. A. ), R. J. Van Brunt (U. S. A. ), and W. Zaengl (Switzerland). The local arrangements committee consisted of members of the Health Sciences Research Division and personnel of the Conference Office of the Oak Ridge National Laboratory, and staff of the University of Tennessee (UTK). The contributions of each member of these committees, the work of the Session Chairmen, the interest of the participants, and the advice of innumerable colleagues are gratefully acknowledged. I am especially indebted to Dr. Isidor Sauers, Dr. David R. James, Mrs.

Review articles on three topics of considerable current interest make up the present volume. The first, on A-hypernuclei, was solicited by the editors in order to provide nuclear physicists with a general description of the most recent developments in a field which this audience has largely neglected or, perhaps, viewed as a novelty in which a bizarre nuclear system gave some information about the lambda-nuclear intersection. That view was never valid. The very recent developments reviewed here-particularly those pertaining to hypernuclear excitations and the strangeness exchange reactions-emphasize that this field provides important information about the models and central ideas of nuclear physics. The off-shell behavior of the nucleon-nucleon interaction is a topic which was at first received with some embarrassment, abuse, and neglect, but it has recently gained proper attention in many nuclear problems. Interest was first focused on it in nuclear many-body theory, but it threatened nuclear physicists'comfortable feeling about nonrelativistic potential theory, and many no doubt hoped that it would remain merely an esoteric diversion within the many-body cult. In the editors' opinion, this subject is now emi nently respectable and a review of it indeed timely. The third topic, nuclear charge distributions, is one which almost every nuclear physicist believed had been weIl in hand for some years."

The authors aim to hone the theory of electron-atom and electron-ion collisions by developing mathematical equations and comparing their results to the wealth of recent experimental data. This first of three parts focuses on potential scattering, and will serve as an introduction to many of the concepts covered in Parts II and III. As these processes occur in so many of the physical sciences, researchers in astrophysics, atmospheric physics, plasma physics, and laser physics will all benefit from the monograph.

Discusses Hahn's contributions to science and his reflections of scientific and social responsibility. The author concludes that Hahn's ideas can still serve as a foundation for responsible and moral actions by scientists.

The Workshop N* Physics and non-perturbative QeD was held at the Eu ropean Center for Theoretical Studies and Related Areas (ECT*) in Trento, Italy, during May 18-29, 1998. Previous workshops of the series on N* Physics took place at the Florida State University (1994), at CEBAF (1995), at the Institute for Nuclear Theory in Seattle (1996) and at the George Washington University (1997). The Workshop was devoted to a summary of recent experimental and the oretical research on N* phsyics and special emphasis was given to the infor mation that photo-and electro-production of nucleon resonances can provide on the non-perturbative regime of Quantum Chromodynamics. The idea was to stimulate discussions among experimentalists and theoreticians in order to pursue the interpretation of the huge amount of forthcoming data from several laboratories in the world. It was therefore decided to have both experimental and theoretical lectures on the main topics, like, among the others, single and double pion production, TJ-and K-meson production, the GDH sum rule, the spin of the proton, etc. Thanks to the unusual two-week extension of the Work shop, the allotted time for the lectures was extended up to one hour in order to allow the invited lecturers to give a detailed presentation of their topics. Fi nally, various short contributions were selected to sharpen the discussion about selected items."