Isospin Dependence Of The Nuclear Equation Of State

本研究将从多个角度提取核物质的态方程（EoS）的同位旋依赖性。利用经典分子动力学（CMD）方法，我们将研究基态核中同位旋对核结合能的依赖，在密度、温度和同位旋条件下的无限核物质，在不同密度、温度和同位旋条件下的激发态核，以及不同同位旋组成的核之间的反应。将要使用的经典分子动力学模型是基于Urbana/Champaign团队获得的质子-质子、中子-中子和质子-中子电位，它没有任何可调参数，也不需要添加产生片段的代码或与反应无关的波动。该项目将研究基态核结合能的等尺度依赖（与不同中子质子比的原子核相关）（以获得Weissacker质量公式的同位旋扩展，并具有对同位旋的显式功能依赖），研究无限核物质的EoS的等尺度依赖（为每个粒子的能量提供解析表达式，并显式依赖于密度，温度和同位旋），研究激发态核的等尺度依赖关系（获得有效的核等尺度依赖关系，可用于从反应中提取实验信息），并将通过研究反应过程中的中子和质子流、同位旋输运比、分馏、双谱比和等尺度来评估等尺度参数作为EoS对称能量项探针的价值。所有的计算都将与密歇根州立大学、德州农工大学和其他加速器的实验数据相关联。这项计划的智力价值在于了解同位旋在核力中未被探索的作用，完善计算模型——可用于测试其他代码，并指导实验人员在密歇根州正在建设的新设施中设计他们的实验。该项目将在德克萨斯大学埃尔帕索分校进行，本科生参加，并与布宜诺斯艾利斯大学的Claudio Dorso教授合作。将努力将西班牙裔学生（包括男性和女性）纳入该项目。该项目的更广泛影响是有利于核物理，为稀有同位素日益增长的物理领域招募学生，支持核物理作为UTEP和埃尔帕索的研究选择，培训本科生的研究方法，并引入西班牙裔学生进入物理研究。

This study will extract the isospin dependence of the Equation of State (EoS) of nuclear matter from several angles. Using classical molecular dynamics (CMD) we will study the dependence of nuclear binding energy on isospin in nuclei on their ground state, in infinite nuclear matter at a range of density, temperature and isospin conditions, in excited nuclei at varying densities,temperatures and isospin, and in reactions between nuclei with different isospin compositions. The classical molecular dynamics model to be used is based on proton-proton, neutron-neutron and proton-neutron potentials obtained by the Urbana/Champaign group, and it does not have any adjustable parameters and does not need the addition of fragment-producing codes or fluctuations extraneous to the reaction. The project will study the isoscaling dependence (relating nuclei with different neutron-proton ratios) of binding energies of ground-state nuclei (to obtain isospin extensions of the Weissacker mass formula with explicit functional dependence on isospin), the study of the isoscaling dependence of the EoS of infinite nuclear matter (to provide analytical expressions for the energy per particle with explicit dependences on density, temperature and isospin), the study of the isoscaling dependence of the EoS of excited nuclei (to obtain an effective nuclear EoS that could be used to extract experimental information from reactions), and it will investigate nuclear reactions to understand how to extract information about the EoS and its isospin dependence through studies of the neutron and proton flow during the reaction, isospin transport ratio, fractionation, double spectral ratios and isoscaling to assess the value of the isoscaling parameters as probes of the symmetry energy term of the EoS. All computations will be linked to experimental data from Michigan State University, Texas A&M University, and other accelerators.The intellectual merit of the proposed activity will be to learn about the unexplored role of isospin in nuclear forces, to refine a computational model - which can be used to test other codes, and to guide experimentalists in designing their experiments in the new facilty under construction in Michigan. The project will be carried out at the University of Texas at El Paso with the participation of undergraduate students and in collaboration with Prof. Claudio Dorso of the University of Buenos Aires. An effort will be made to incorporate Hispanic students (both male and female) into this project. The broader impact of the project is a benefit to nuclear physics, the recruitment of students to the growing physics area of rare isotopes, the support of nuclear physics as a research option at UTEP and in El Paso, the training of undergraduate students in research methodology, and the introduction of Hispanic students into physics research.