Research Topics in Theoretical Nuclear and Neutrino Physics

该项目将使用理论方法探索核科学与天体物理学和高能物理学接口的一些基本问题。这些问题包括从氘到铀的元素在宇宙中是在哪里以及如何产生的，以及被称为中微子的基本粒子对元素产生的影响，以及在所观测的宇宙中物质相对于反物质的宇宙丰度不对称的起源。该项目还将研究极低能量下的核反应机制。这项研究有助于支持核科学方面的国家科学优先事项，特别是密歇根州立大学校园正在建设的稀有同位素束设施，这是一个世界领先的核结构、反应和天体物理学研究实验室。在这里开展的研究工作也将有助于培养下一代科学家，使他们能够参加能够在不同环境中工作的竞争性劳动力。超新星核心坍缩后，冷却的原中子星星发射出大量的中微子，这使得在描述超新星中的中微子输运时必须考虑中微子-中微子相互作用。这个多中微子系统的集体模的对称性及其对超新星中快速中子俘获核合成的影响将被研究。最近在星系团的X射线光谱中发现了一条不明的发射线，这可以解释为一个衰变的7 keV无菌中微子产生的信号，它与活跃的中微子混合。研究人员和他的学生将探索这种状态在反应堆实验中的影响，并评估这种状态存在的可能性。他们还将探索中微子磁相互作用对大爆炸核合成的影响，以及利用对称性理解双β衰变核矩阵元素的各种方法。最后，PI将根据有效场论的最新经验重新研究两个原子核之间的相互作用势，迄今为止，有效场论仅适用于核子-核子相互作用。

This project will use theoretical methods to explore some of the fundamental questions at the interface of nuclear science with astrophysics and high-energy physics. These questions include where and how elements from deuterium to uranium are made in the Universe and the effect of the elementary particles called neutrinos on the production of elements and the origin of the asymmetry in the cosmic abundance of matter over antimatter in the observed Universe. This project will also examine nuclear reaction mechanisms at very low energies. This research contributes to the support of national scientific priorities in Nuclear Science, in particular to the Facility for Rare Isotope Beams under construction at the Michigan State University campus, a world-leading laboratory for the study of nuclear structure, reactions and astrophysics. The research efforts to be carried out here will also contribute to the training of next generation of scientists, enabling them to take part in a competitive workforce capable of performing in diverse settings. The sheer number of neutrinos emitted from a cooling proto-neutron star following the collapse of a supernova core necessitates inclusion of neutrino-neutrino interactions in the description of the neutrino transport in supernovae. Symmetries of the collective modes of this many-neutrino system and their impact on the rapid neutron capture nucleosynthesis in supernovae will be investigated. An unidentified emission line was recently seen in the X-ray spectrum of galaxy clusters that could be interpreted as a signal emerging from a decaying seven keV sterile neutrino, which mixes with the active ones. The investigator and his students will explore the effects of such states in reactor experiments and assess the likelihood of existence of such a state. They will explore also effects of neutrino magnetic interactions on Big Bang Nucleosynthesis, together with various ways to exploit symmetries in understanding double beta decay nuclear matrix elements. Finally, the PI will re-examine the interaction potential between two nuclei in the light of the recent experience with the effective field theory, hitherto applied only to the nucleon-nucleon interactions.