US-Tunisia Cooperative Research: Medium Modifications of the N-N Interaction Studied in Large-Basis Shell-Model Calculations

University Of Arizona, Tucson AZ

Investigators

Abstract

0096785 Barrett Description: This award is for support of a joint research project by Dr. Bruce R. Barrett, Professor, Department of Physics, University of Arizona, Tucson, Arizona and Dr. Mohamed Slim Fayache, Assistant Professor, Physics Department, University of Tunis, Tunis, Tunisia. The research addresses one of the long-standing problems in nuclear-structure physics, that of how the free-space interaction between two nucleons (protons and /or neutrons) is modified inside a nucleus (i.e., inside nuclear matter). One of these two scientists has previously performed calculations to study these medium-modification effects on the tensor and spin-orbit components of the nucleon-nucleon interaction, but only in a fairly limited model space for the interacting nucleons. New theoretical techniques in the form of the large-basis, no-core shell-model approach now permit such calculations in significantly larger model spaces. The two investigators will study how the medium-modification effects on the nucleon-nucleon interaction are changed by extending the calculations to model spaces beyond excitations of 2hw. Other nuclear-structure problems will also be investigated using the large-basis, no-core shell-model method, such as the properties of nuclei far from the valley of stability. Scope: This award will allow a US scientist to collaborate with a Tunisian scientist in an area where each has knowledge of different and unique methods for solving certain theoretical physics problems. The problem to be addressed, the microscopic calculations of nuclear structures, is one in which the PI and other US scientists are fully engaged. This proposal meets the INT objective of supporting US-foreign scientific collaboration in areas of mutual benefit. Funding for this project is provided by the Division of International Programs and the Division of Physics.