U.S.-Brazil Collaborative Research: Non-Equilibrium and Isospin Effects in Nuclear Fragmentation

在美国-巴西合作项目，由美洲计划，威廉G。Lynch和ManYee B。密歇根州立大学的Tsang和William A.威斯康星州大学的弗里德曼将与里约热内卢联邦大学理论小组的劳尔·多安杰洛和塞尔吉奥·苏扎合作。 这些研究人员将进行协调研究，以解释实验多重碎片数据。 这项调查的主要重点是识别和建模的非平衡现象，影响调查的同位旋依赖的液体-气体相变和核状态方程。 这项研究涉及到数据的详细比较，以国家的最先进的平衡统计多重碎片模型和扩大蒸发源模型，已开发的PI的。 它还涉及到新的非平衡模型的比较，将在项目期间开发的合作。 这些结果将有助于确定大多数平衡模型所假设的平衡冻结结构的准确程度，并有助于开发可以分析具有显着非平衡贡献的数据的形式主义。这种非平衡现象的合作调查是一种重点突出的理论努力，扩展了国家超导回旋加速器实验室（NSCL）所做的实验工作。在密歇根州立大学以及其他实验室。 该项目需要美国和巴西主要研究人员的专业知识，不仅是解释NSCL反应计划数据的关键，也是解释其他飞行中稀有同位素设施研究数据的关键。

In this U.S.-Brazil collaborative project funded by the Americas Program, William G. Lynch and ManYee B. Tsang of Michigan State University and William A. Friedman of the University of Wisconsin will work with Raul Donangelo and Sergio Souza of the theory group at the Federal University of Rio de Janeiro. These researchers will make a coordinated study to interpret experimental multifragmentation data. The major focus of this investigation is on the identification and modeling of non-equilibrium phenomena that influence investigations of the isospin dependence of the liquid-gas phase transition and of the nuclear equation of state. The research involves detailed comparisons of data to state-of-the-art equilibrium Statistical Multifragmentation Models and to the Expanding Evaporating Source models that have been developed by the PI's. It also involves comparisons to new non-equilibrium models that will be developed by this collaboration during the project. The results will help to determine the degree to which the equilibrated freezeout configuration assumed by most equilibrium models is accurate and to develop formalisms with which one can analyze data with significant non-equilibrium contributions.This collaborative investigation of non-equilibrium phenomena is a well-focused theoretical effort that extends the experimental work done at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University as well as at other laboratories. The project requires the expertise of both the U.S. and Brazilian principal investigators and is key to interpreting data from not only reaction programs at NSCL but also research at other in-flight rare isotope facilities.