中法核工程与技术学院核声论坛（总第222期）

讲座摘要：

A growing body of evidence suggests that we may not yet fully understand highly excited nuclei. According to random matrix theory (which assumes such strong dynamical correlations that the underlying physical structure completely disappears), highly excited nuclei are typically chaotic. However, with new breakthroughs in nuclear many-body techniques, our calculations of nuclear level density, gamma-ray strength functions, and Gamow-Teller strength distributions show that for the highly excited states under consideration, even those with extremely high spin and energy, structurally relevant properties remain clearly visible. Recently, we proposed that states might appear chaotic in a traditional view and yet be highly ordered topologically if the order parameter is the Chern number invisible to usual local measurements. This new understanding could have significant implications for nuclear astrophysics, nuclear fission, and nuclear waste transmutation, where highly excited compound nuclei are involved.

主讲人简介：

孙扬，上海交通大学物理与天文学院教授。1985年获阿登纳基金会资助赴德国留学,1991年获德国慕尼黑工业大学理论核物理博士学位；其后多年在欧洲和美国工作,包括西班牙马德里自治大学、美国橡树岭国家实验室、田纳西大学及圣母大学；2007年起受聘于上海交通大学。中国物理学会吴有训奖获得者，曾任CGS16国际核物理大会主席。长期深耕教学一线，主讲物理本科《量子力学》和全校通识课《核能历史和未来》、以及研究生《量子多体问题》和《核天体物理基础》。从事原子核理论以及与核物理相关的交叉研究工作,是投影壳模型的创始人之一，并独立发展了该模型。近年来的研究兴趣主要集中在原子核多体问题和与天体核过程中的核结构与反应，以及强关联量子体系的集体运动和相变等方面。发表学术论文350余篇，出版学术著作《Symmetry, Broken Symmetry, and Topology in Modern Physics》(Cambridge University Press)、《天文学教程（上、下册）》(上海交通大学出版社)。