US-Norway Cooperative Research: Energetic Nuclear Collisions

该奖项支持肯特州立大学物理系的George Fai教授和劳伦斯伯克利实验室核科学部的Joergen Randrup博士与挪威卑尔根大学物理系的Laszlo P. Csernai教授和Jan S. Vaagen教授的一项研究合作。他们研究的总体目标是实现对相对论性核碰撞的理论理解，重点是受激核物质的一般性质和可能的相变。他们将对出现在相对论性重离子碰撞中的核物质的集体性质进行几个密切相关的理论研究。更具体地说，他们正在寻求通过包括碎片之间的吸引核相互作用和库仑相互作用来改进现实的核解体微规范模拟模型。他们还将通过经典模拟模型研究中能重离子碰撞动力学、集体横向流动特性和最终破碎动力学。此外，他们对超相对论性核碰撞和夸克-胶子等离子体（QGP）形成的动力学也很感兴趣。这些和其他类型的模型将用于在两个基本能量区域检查核物质的性质：目前在欧洲核子研究中心和布鲁克海文国家实验室进行实验研究的最高能量，以及可以研究核多重碎片和液-气相变的中间能量反应。美国研究人员开发了一种最详细的中能量统计碎裂模型，并将提供该领域的专业知识，而挪威参与者则从事几种能量的流体动力学研究，并带来了与低能核-核相互作用相关的专业知识。理论与实验的不断相互作用使核物理学领域的进步成为可能。这次合作的理论结果将为分析实验数据和设计新的实验提供有用的工具。由于统计方法被广泛使用，该研究可以提供对小系统的统计的见解，使用核作为一个试验场。

This award supports Professor George Fai of the Department of Physics, Kent State University, and Dr. Joergen Randrup of the Nuclear Science Division of Lawrence Berkeley Laboratory, in a research collaboration with Professors Laszlo P. Csernai and Jan S. Vaagen, of the Physics Department, University of Bergen, Norway. The general aim of their research is to achieve a theoretical understanding of relativistic nuclear collisions, with emphasis on the general properties of excited nuclear matter and possible phase transitions. They will carry out several closely related theoretical investigations of the collective properties of nuclear matter as they appear in relativistic heavy ion collisions. More specifically, they are seeking to improve realistic microcanonical simulation models of nuclear disassembly by including the attractive nuclear interactions and Coulomb interactions among the fragments. They will also study the dynamics of intermediate energy heavy ion collisions via classical simulation models, the properties of collective transverse flow and the dynamics of final fragmentation. In addition, they are interested in the dynamics of ultrarelativistic nuclear collisions and of quark-gluon plasma (QGP) formation. These and other types of models will be used to examine the properties of nuclear matter at two basic energy regions: the highest energies now under experimental investigation at CERN and Brookhaven National Laboratory, and intermediate energy reactions where nuclear multifragmentation and liquid-vapor phase transition can be studied. The U.S. investigators have developed one of the most detailed statistical fragmentation models at medium energies and will provide expertise in this area, while the Norwegian participants have worked in fluid dynamics at several energies and also bring expertise related to nucleus-nucleus interaction at low energy. Advances in the field of nuclear physics are made possible by the continuing interaction between theory and experiment. The theoretical results of this collaboration will provide useful tools for analyzing experimental data and designing new experiments. Since statistical methods are used extensively, the research can provide insight in the statistics of small systems, using nuclei as a proving ground.