Green's Functions and The Nuclear Many-Body Problem

Washington University, Saint Louis MO

Investigators

Abstract

This research project has the overall goal of increasing our knowledge of nuclear systems both finite and infinite. Particular emphasis is placed on the physics of nuclei with large neutron or proton excess with the intent to provide theoretical support and predictions for experiments at rare isotope facilities, including the new generation at RIKEN Tokyo, GSI Darmstadt, and NSCL/MSU East Lansing. Since most experiments at such facilities employ strongly interacting probes, an improved analysis of such reactions is proposed in order to extract new physics. The serious discrepancies between heavy-ion knockout and transfer reactions make this development urgent. The tool for this research project is the dispersive optical model, based on the Green's function method, which provides a bridge between nuclear reactions and nuclear structure information. Ab initio microscopic calculations of heavier and exotic nuclei are proposed based on the Faddeev random phase approximation (FRPA) formulation of the self-consistent Green's function method. This many-body approach appears to be one of the most promising strategies to deal with medium and heavy nuclei for the calculation of the ground state as well as spectroscopic data. The proposal also outlines concrete steps to clarify the phase diagram of nuclear matter around saturation density, as a function of temperature and nucleon asymmetry. The research intends to raise the standard of the analysis of nuclear reactions and is intended to have a significant impact on the experimental program at facilities like the planned Facility for Rare Isotope Beams (FRIB). The ab initio FRPA method practiced in the group provides interdisciplinary links with other fields and involves international collaborations with institutions in England, Japan, Spain, and Belgium. The continued exposure of graduate students and young scientists all over the world to the many-body theory book of the PI fosters improved understanding of exciting new phenomena in nuclear physics in other disciplines. The mentoring of graduate assistants and post-doctoral associates in the process and ethic of scientific research is an integral part of the project. Their development toward independence as original and productive scientists is a central objective of the program and will continue to prepare them for industry or academic institutions.