Quantum Description of Central Nuclear Reactions

中心核碰撞的动力学涉及许多核成分的同时和非平凡的相互作用。这种相互作用是对原子核理论的挑战，对研究早期宇宙的物理也很重要。不幸的是，目前对核碰撞的描述依赖于动力学的半经典极限。克服了以前在核反应量子理论的数值实现中的技术困难，在这个项目中，研究人员和他的合作者将在攻击现实的三维情况之前，开发一维和二维多体理论的数值实现的新策略。由此带来的核碰撞软件基础设施的升级将支持密歇根州立大学校园内目前正在建设的未来稀有同位素束设施的实验计划。该项目开发的计算方法可能有助于其他领域的研究，如电子工程中纳米级电子设备之间的电子传输研究，并将培训参与尖端计算技术的博士后和学生。该项目旨在开发基于非平衡格林函数方法的中心核碰撞定量描述的计算框架，有望开辟通往核反应第一性原理描述的道路。通过遵循多体系统的量子演化而不是半经典演化，Pi和他的合作者将减少能量碰撞分析中的不确定性，以研究体核性质，包括对称能量和物质的输运性质。该项目的成功完成将为研究迎面核碰撞和集体共振激发提供有用的工具，并将为今后研究有限碰撞参数下的碰撞奠定基础。

The dynamics of central nuclear collisions involves simultaneous and nontrivial interactions of many nuclear constituents. Such interactions are a challenge for nuclear theory and are important for studies of the physics of the early Universe. Unfortunately, current descriptions of nuclear collisions rely on the semiclassical limit of the dynamics. Overcoming previous technical difficulties in the numerical implementation of the quantal theory of nuclear reactions, in this project the investigator and his collaborators will develop new strategies for the numerical implementation of this many-body theory in one and two dimensions, before attacking the realistic three-dimensional case. The resulting upgrade in software infrastructure for nuclear collisions will support the experimental program at the future Facility for Rare Isotope Beams currently under construction on the Michigan State University campus. The computational methods developed in this project are likely to benefit research in other fields, such as studies of electron transport across nanoscale electronic devices in electrical engineering, and will train the postdoc and student involved in cutting-edge computational techniques.This project aims to develop the computational framework for a quantal description of central nuclear collisions based on a nonequilibrium Green functions approach that is expected to open up the path towards a first-principles description of nuclear reactions. By following the quantal rather than the semiclassical evolution of many-body systems, the PI and his collaborators will reduce the level of uncertainty in the analysis of energetic collisions for the study of bulk nuclear properties, including the symmetry energy and the transport properties of matter. The successful completion of this project will provide useful tools for studies of head-on nuclear collisions and excitations of collective resonances, and will prepare the ground for future studies of collisions at finite impact parameter.