Spin and Isospin in Nuclear Interactions


Book Description

This volume contains the proceedings of an International Conference on "Spin and Isospin in Nuclear Interactions", which was held in Telluride, Colorado USA, 11-15 March 1991. This was the fifth in a series of conferences held in Telluride every three years since 1979. In attendance at the conference were just under 100 participants, representing a total of 43 institutes from 12 different countries. In keeping with previous Telluride conferences, the role of spin and isospin degrees of freedom in both nuclear structure and nuclear interactions remained an important theme. Topics covered included new results on the spin- and isospin-dependent terms in the free and effective nucleon-nucleon interaction, Gamow-Teller excitations, charge and spin exchange with hadronic probes, and spin measurements with leptonic probes. Recent progress in the development of polarized sources, polarized targets, and po larimetry was also discussed, as were applications to neutrino physics and astrophysics. Whereas earlier Telluride conferences had dealt primarily with nucleon-nucleus inter actions, this meeting included extensive discussions on the role of spin and flavor in particle interactions, and on ways of "bridging the gap" between concepts usually as sociated with particle physics and the domain of more conventional nuclear physics. The conference consisted of morning and evening scientific sessions, leaving the afternoons free for informal discussions, recreation, and enjoyment of the scenic beauty of the Telluride area. In addition to the invited talks, time was allotted for contributed talks on new results.







Spin Excitations in Nuclei


Book Description

This volume contains the proceedings of the "International Conference on Spin Excitations in Nuclei" held in Telluride, Colo rado, March 25-27, 1982. The motivation for the conference was, in a large part due to the recent development of new variable energy accelerators which produce high quality beams of electrons, protons, and pions that are providing the first precise information on spin excitations in nuclei over a large range of spin and mass. In the past such data had been restricted primarily to light nuclei and were generally resolution limited. Perhaps, the most exciting new result has been the clear observation of the elusive spin-dipole strength (Gamow Teller and Ml) in medium and heavy mass nuclei through the use of the (p,n) and (p,p') reactions at or near zero degrees with 100-200 MeV incident protons. Energy dependence in the isovector parts of the nucleon-nucleon interaction make the 100-200 MeV energy region particularly appropriate for such studies. The clean data from (e,e'), ('IT,'IT'), (p,p'), and (p,n) on high spin "stretched" states which have particularly simple structure has also been quite impor tant. The recent results contain important new information on the nature of the spin dependent forces in nuclei. These in turn are inherently related to the properties of the nuclear mesonic field and the underlying quantum chromodynamics.




The Nucleon Spin as Cause of the Strong Interaction


Book Description

This work is a translation of the German edition "Der Nukleonenspin als Ursache der starken Wechselwirkung". (Dec. 2020). The strong interaction is supposed to describe the forces which are active in the atomic nucleus between the nuclear building blocks. Until today, however, it has not been possible to design a theory free of contradictions. Instead, in the 1970s, the theory of "quantum chromodynamics" emerged, in which the name itself is based on an analogy. Just like the "color charges" mentioned as cause of the interaction. The question is only: Analogy to what and due to which energy? Because either it refers to the electric energy, then there would have to be some kind of electric parallel energy, but this is nonsensical. Or it doesn't refer to the electric energy, then it must be a form of energy which already exists. But quantum chromodynamics makes no statement about this. This QCD theory standing on shaky feet thus virtually challenges the contradiction. In order to oppose this very artificial theory with a down-to-earth one, it is important to keep in mind the basics of the known interactions. All particle systems can build up only if their particles have besides their energy also an opposite property by which they can interact. The simplest system is a binary system, e.g. a common salt crystal. The opposite properties are the electrically positive and negative charge of the ions. But which opposite property enables an interaction of the nucleons? It cannot be an electric charge. The astonishing answer to this question is given in this paper at the end. It also becomes clear that quantum chromodynamics is a fallacy. For a better understanding, contents of earlier publications of the author are partly included.







Nuclear Physics


Book Description

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.




The (p,n) Reaction and the Nucleon-Nucleon Force


Book Description

This volume contains the proceedings of the "Conference on the (p,n) Reaction and the Nucleon-Nucleon Force" held in Telluride, Colorado, March 29-31, 1979. The idea to hold this conference grew out of a program at the Indiana University Cyclotron Facility to study the (p,n) reaction in the 50-200 MeV energy range. The first new Indiana data, in contrast to low energy data, showed features suggestive of a dominant one pion exchange interaction. It seemed desir able to review what was known about the fre·e and the effective nucleon-nucleon force and the connection between the low and high energy (p,n) data. Thus the conference was born. The following people served as the organizing committee: S. M. Austin, Michigan State University W. Bertozzi, Massachusetts Institute of Technology S. D. Bloom, Lawrence Livermore Laboratory C. C. Foster, Indiana University C. D. Goodman, Oak Ridge National Laboratory (Conference Chairman) D. A. Lind, University of Colorado J. Rapaport, Ohio University G. R. Satch1er, Oak Ridge National Laboratory G. E. Walker, Indiana University R. L. Walter, Duke University and TUNL The sponsoring organizations were: Indiana University, Bloomington, Indiana University of Colorado, Boulder, Colorado Oak Ridge National Laboratory, Oak Ridge, Tennessee Triangle Universities Nuclear Laboratory, Durham, North Carolina Of course, the major credit for the success of the con ference must go to the speakers who diligently prepared their talks that are reproduced in this volume.




An Assessment of U.S.-Based Electron-Ion Collider Science


Book Description

Understanding of protons and neutrons, or "nucleons"â€"the building blocks of atomic nucleiâ€"has advanced dramatically, both theoretically and experimentally, in the past half century. A central goal of modern nuclear physics is to understand the structure of the proton and neutron directly from the dynamics of their quarks and gluons governed by the theory of their interactions, quantum chromodynamics (QCD), and how nuclear interactions between protons and neutrons emerge from these dynamics. With deeper understanding of the quark-gluon structure of matter, scientists are poised to reach a deeper picture of these building blocks, and atomic nuclei themselves, as collective many-body systems with new emergent behavior. The development of a U.S. domestic electron-ion collider (EIC) facility has the potential to answer questions that are central to completing an understanding of atoms and integral to the agenda of nuclear physics today. This study assesses the merits and significance of the science that could be addressed by an EIC, and its importance to nuclear physics in particular and to the physical sciences in general. It evaluates the significance of the science that would be enabled by the construction of an EIC, its benefits to U.S. leadership in nuclear physics, and the benefits to other fields of science of a U.S.-based EIC.




The Nucleon-nucleon Interaction and the Nuclear Many-body Problem


Book Description

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.