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教授合作进行研究。他们研究的总体目标是实现对相对论核碰撞的理论理解，重点是激发核物质的一般性质和可能的相变。他们将对核物质在相对论重离子碰撞中出现的集体性质进行几项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吸引人的核相互作用和库仑相互作用来改进核拆解的现实微正则模拟模型。他们还将通过经典模拟模型研究中能重离子碰撞的动力学，集体横流的性质和最终碎裂的动力学。此外，他们还对极端相对论核碰撞和夸克-胶子等离子体(QGP)形成的动力学感兴趣。这些模型和其他类型的模型将被用来研究两个基本能区的核物质的性质：欧洲核子研究中心和布鲁克海文国家实验室目前正在进行实验研究的最高能量，以及可以研究核多重碎裂和液-气相变的中能反应。美国研究人员在中等能量下开发了最详细的统计碎裂模型之一，并将提供这一领域的专业知识，而挪威的参与者在几个能量下从事流体动力学工作，并带来了与低能核-核相互作用相关的专业知识。理论和实验之间的持续互动使核物理领域的进步成为可能。这一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，这项研究可以利用原子核作为试验场，对小系统的统计提供洞察力。

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.