Dr. Witold (Witek) Nazarewicz

NUCLEAR PHYSICS

Nuclear Structure

Atomic nuclei, the core of matter and the fuel of stars, are self-bound collections of protons and neutrons (nucleons) that interact through forces that have their origin in quantum chromo-dynamics. Nuclei comprise 99.9% of all baryonic matter in the Universe. The complex nature of the nuclear forces among protons and neutrons yields a diverse and unique variety of nuclear phenomena, which form the basis for the experimental and theoretical studies. Developing a comprehensive description of all nuclei, a long-standing goal of nuclear physics, requires theoretical and experimental investigations of rare atomic nuclei, i.e. systems with neutron-to-proton ratios larger and smaller than those naturally occurring on earth. The main area of my professional activity is the theoretical description of those exotic, short-lived nuclei that inhabit remote regions of nuclear landscape. Key scientific themes that are being addressed by my research are captured by overarching questions:

• What is the nature of the nuclear force that binds protons and neutrons into stable nuclei and rare isotopes?
• What are the limits of nuclear existence?
• What is the origin of simple patterns in complex nuclei?
• How can our knowledge of nuclei and our ability to produce them benefit the humankind?

Quantum Many-Body Problem

Heavy nuclei are splendid laboratories of many-body science. While the number of degrees of freedom in heavy nuclei is large, it is still very small compared to the number of electrons in a solid or atoms in a mole of gas. Nevertheless, nuclei exhibit behaviors that are emergent in nature and present in other complex systems. For instance, shell structure, symmetry breaking phenomena, collective excitations, and superconductivity are found in nuclei, atomic clusters, quantum dots, small metallic grains, and trapped atom gases.

Although the interactions of nuclear physics differ from the electromagnetic interactions that dominate chemistry, materials, and biological molecules, the theoretical methods and many of the computational techniques to solve the quantum many-body problems are shared. Examples are ab-initio and configuration interaction methods, and the Density Functional Theory, used by nuclear theorists to describe light and heavy nuclei and nucleonic matter.

Physics of Open Systems

Today, much interest in various fields of physics is devoted to the study of small open quantum systems, whose properties are profoundly affected by environment, i.e., continuum of decay channels. Although every finite fermion system has its own characteristic features, resonance phenomena are generic; they are great interdisciplinary unifiers. In the field of nuclear physics, the growing interest in theory of open quantum systems is associated with experimental efforts in producing weakly bound/unbound nuclei close to the particle drip-lines, and studying structures and reactions with those exotic systems. In this context, the major problem for nuclear theory is a unification of structure and reaction aspects of nuclei, that is based on the open quantum system many-body formalism. Solution of this challenging problem has been advanced recently through the new-generation continuum shell model approaches, in particular the Gamow Shell Model based on the Berggren ensemble. The recent development of the Density-Matrix Renormalization Group algorithm for open quantum systems within the rigged Hilbert space formulation of quantum mechanics, enables presently fully converged configuration interaction calculations.

Brief Vita

Dr. Nazarewicz is the author of seven review papers and more than 270 refereed publications in scientific journals. He is listed by ISI among the most highly-cited physicists. He has also made more than 150 contributions to major conferences, published in their respective proceedings. He has given ~165 invited talks at major international conferences and more than 200 invited seminars and colloquia. Dr. Nazarewicz has helped organize more than 30 meetings and conferences and presently serves on 14 professional committees and editorial boards.

Professor Nazarewicz's Full CV

Selected Publications

Complete List of Professor Nazarewicz's Papers

Selected Links

• Physics Division, ORNL
• Holifield Radioactive Ion Beam Facility
• Institute of Theoretical Physics, Physics Department, Warsaw University
• The Joint Institute for Heavy Ion Research
• The Japan-U.S. Theory Institute for Physics with Exotic Nuclei
• Reviews of Modern Physics
• The European Physical Journal A
• National Institute for Nuclear Theory
• European Centre for Theoretical Studies in Nuclear Physics and Related Areas
• American Physical Society Division of Nuclear Physics
• DOE/NSF Nuclear Science Advisory Committee

Teaching, Education

• Nuclear Physics 621
• Nuclear Physics 622: Fermionic Many-Body Problem
• Graduate Research Participation Seminar 599
• Nuclear Physics Seminar P599-2

Research

• Witek's ISI Highly Cited Web site
• Papers on eprintweb
• Nuclear Physics Research at the University of Tennessee
• Nuclear Theory Group, ORNL
• Theoretical Description of the Fission Process
• Universal Nuclear Energy Density Functional (UNEDF)
• FIDIPRO Project