U.S.-Lithuanian Cooperative Research: Techniques for Performing Microscopic Nuclear Structure Calculations

INT-9806614巴雷特美国-立陶宛合作研究奖授予美国亚利桑那大学的布鲁斯·R·巴雷特博士和立陶宛维尔纽斯物理研究所的拉穆蒂斯·卡里诺斯卡斯博士和考纳斯的维塔亚斯·马格努斯大学的金陶塔斯·卡蒙塔维修斯博士之间的一个项目，该项目是关于执行微观核结构计算的技术。核物理学的一个主要目标是了解单个核子之间的潜在相互作用是如何产生核的结合、稳定性和结构的。多年来，只精确计算具有真实核子-核子(NN)相互作用的三体和四体原子核是可行的。最近，一些新的NN势被构造出来，如Nijmegen、Argonne V18和CD-Bonn。它们高精度地拟合了350 MeV以下pp和np散射的世界数据，x2/datum约为1。由于计算资源的进步，现在有可能将这种NN相互作用应用于大基无核壳模型和量子蒙特卡罗计算，以研究轻p壳核的性质。对A=6和7原子核，包括所有观测到的低激发态，进行了这样的计算。在这些工作中，有可能看到核壳结构是从微观相互作用中发出的，符合NN散射数据。要以类似的方式描述和预测较大的A核的核结构性质，将需要更多的理论工作。拟议项目的目标是对现有计算方法进行修改，以便它们可以用于研究较重质量的核。这项理论核物理研究实现了将美国和立陶宛的顶尖专家聚集在一起，在平等、互惠和互利的基础上，在共同利益和能力强的领域结合互补努力和能力的计划目标。*

INT-9806614BarrettThis U.S.-Lithuania Cooperative Research award is for a project on "Techniques for Performing Microscopic Nuclear Structure Calculations" between Dr. Bruce R. Barrett of the University of Arizona, for the U.S. side, and, for the Lithuanian side, Dr. Ramutis Kalinauskas of the Institute of Physics in Vilnius, and Dr. Gintautas Kamuntavicius of Vytaytas Magnus University in Kaunas. A major goal in nuclear physics is to understand how nuclear binding, stability and structure arise from the underlying interactions between individual nucleons. For many years, it has been feasible to calculate exactly only three- and four-body nuclei with realistic nucleon-nucleon (NN) interactions. Recently, several new NN potentials, such as the Nijmegen, the Argonne V18 and CD-Bonn, have been constructed. They fit the world data for pp and np scattering below 350 MeV with high precision and yield a x2/datum of about 1. Due to advances in computing resources, it is now possible to apply such NN interactions in large-basis No-core Shell-model and Quantum Monte Carlo calculations to study the properties of light p-shell nuclei. Such calculations for the A = 6 and 7 nuclei, including all the observed low-lying excitations, have been reported. In these works, it is possible to see nuclear-shell structure emanating from a microscopic interaction that fits NN scattering data. To describe and predict nuclear-structure properties in a similar manner for larger A nuclei will require much more theoretical work. the goal of the proposed project is to develop modifications to the existing calculational methods, so that they may be used for investigating heavier-mass nuclei.This research in theoretical nuclear physics fulfills the program objectives of bringing together leading experts in the U.S. and Lithuania to combine complementary efforts and capabilities in areas of strong mutual interest and competence on the basis of equality, reciprocity, and mutuality of benefit.***