Interaction Of A Nucleon With The Nucleus

Dramatic progress has been made in all branches of physics since the National Research Council's 1986 decadal survey of the field. The Physics in a New Era series explores these advances and looks ahead to future goals. The series includes assessments of the major subfields and reports on several smaller subfields, and preparation has begun on an overview volume on the unity of physics, its relationships to other fields, and its contributions to national needs. Nuclear Physics is the latest volume of the series. The book describes current activity in understanding nuclear structure and symmetries, the behavior of matter at extreme densities, the role of nuclear physics in astrophysics and cosmology, and the instrumentation and facilities used by the field. It makes recommendations on the resources needed for experimental and theoretical advances in the coming decade.

This book provides a comprehensive overview of some key developments in the understanding of the nucleon-nucleon interaction and nuclear many-body theory. The main problems at the level of meson exchange physics have been solved, and we have an effective field theory using a phenomenological interaction pioneered by Achim Schwenk and Scott Bogner, which is nearly universally accepted as a unique low-momentum interaction that includes all experimental data to date.This understanding is based on a multi-step development in which different scientific insights and a wide range of physical and mathematical methodologies fed into each other. It is best appreciated by looking at the different 'steps along the way', starting with the pioneering work of Brueckner and his collaborators that was just as necessary and important as the insightful masterly improvements to Brueckner's theory by Hans Bethe and his students. Moving on from there, the off-shell effects that bedeviled Bethe's work — which had resulted in the 1963 Reference Spectrum Method — were treated relatively accurately by introducing an energy gap between initial bound states and an intermediate state. With their influential 1967 paper, Brown and Kuo prepared the effective field theory. Later, the introduction of 'Brown-Rho scaling' deepened understanding of saturation in the many-body system and fed directly into recent work on carbon-14 dating.

This book provides a comprehensive overview of some key developments in the understanding of the nucleon-nucleon interaction and nuclear many-body theory. The main problems at the level of meson exchange physics have largely been solved, and we now have an effective nucleon-nucleon interaction, pioneered in a renormalization group formalism by several of us at Stony Brook and our colleagues at Naples, which is nearly universally accepted as the unique low-momentum interaction that includes all experimental information to date.Our present understanding of these issues is based on a multi-step development in which different scientific insights and a wide range of physical and mathematical methodologies fed into each other. It is best appreciated by looking at the ‘steps along the way’, starting with the pioneering work of Brueckner and his collaborators that was just as necessary and important as the insightful improvements to Brueckner's theory by Hans Bethe and his students. Moving on from there, microscopic methods for nuclear structure calculations using the Brueckner G-matrix, and later low-momentum nucleon interactions, were developed and applied. With their influential 1967 paper, Brown and Kuo prepared the effective theory that allowed the description of nuclear properties directly from the underlying nucleon-nucleon interaction. Later, the addition of ‘Brown-Rho scaling’ to the one-boson-exchange model deepened the understanding of nuclear matter saturation, carbon-14 dating and the structure of neutron stars.

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.

This book shows the usefulness of the nucleus as a laboratory for learning about basic symmetries and fundamental interactions. It is aimed at advanced graduate students and beginning researchers, but should be useful to advanced researchers as well. Nuclear and particle physicists will find it particularly useful.

The present text grew out of a number of lecture courses for advanced under graduate and new graduate students in nuclear physics. They were given at summer schools in Leuven, Melbourne, and at study weeks for Dutch grad uate students which aimed to emphasize fundamental and topical aspects of nuclear physics. On occasion, part of the present text was presented to stu dents from a much wider field than just nuclear physics and also within a number of general physics colloquia, where, in addition to nuclear physicists, physicists from many other fields were present. In this respect, the intention is to present, in an amply illustrated form, the key quest ions that arise in nuclear physics. At the same time we try to show why a better understanding of the atomic nucleus is not only important in itself, but also yields essential insights into the many connections to other fields of physics. We thus concen trate on the unifying themes rather than addressing in great detail particular subfields of nuclear physics. The present project does not aim to be another comprehensive textbook on nuclear physics: Many of the detailed technical arguments that enter into the picture are not developed here as they would be in a more standard textbook. Instead they are presented using analogies, quite often with simple pictures and arguments that try to convey the general line of thinking and working in nuclear physics.