Nuclear, Particle, and Weak Interaction Physics of the Big Bang and Stellar Collapse

该项目探索中微子和原子核的基础物理，一方面利用核物理学和中微子物理学令人兴奋的新发展的交叉点，另一方面利用日益复杂的天体物理学和天文学对致密物体、核合成历史和宇宙学的探测。这项事业的一个关键问题将是研究中微子如何在致密物质中相互作用，以及这些相互作用如何导致中微子改变它们的味道。为此，加州大学圣地亚哥分校将努力：(1)制定和理解在一般介质中控制中微子风味演化的量子动力学方程；(2)构建各种超新星、恒星坍缩和致密天体并合环境中中微子风味演化的大规模数值模拟，并评估这种中微子风味物理对这些场所原子核合成前景的反馈；(3)了解高温环境下的中微子-核相互作用、核配分函数和弱强度分布；(4)评估中微子领域的不确定性和新的超越标准模型的可能性如何影响核合成、暗物质、致密物体物理学和宇宙学的思想，并着眼于发现实验室中无法获得的约束条件。该项目支持的研究将为原子核和辐射在极端温度和密度条件下的行为提供见解。反过来，这些见解可以为一些基本粒子的性质和元素的起源提供重要线索，例如，在超新星爆炸的炽热内部，或者在宇宙只有几秒钟的时候。这些基本问题将为青年科学家、核物理学家在研究生和本科两级的培训提供独特的机会。

This project probes the fundamental physics of neutrinos and nuclei by exploiting the intersection of exciting new developments in nuclear physics and neutrino physics on the one hand, and the increasingly sophisticated astrophysical and astronomical probes of compact objects, nucleosynthesis histories, and cosmology on the other. A key issue in this enterprise will be studying how neutrinos interact in dense matter and how these interactions may cause neutrinos to change their flavors. To these ends, this UCSD effort will work toward: (1) Formulating and understanding the quantum kinetic equations which govern neutrino flavor evolution in a general medium; (2) Constructing large-scale numerical simulations of neutrino flavor evolution in various supernova, stellar collapse, and compact object merger environments and assessing the feedback of this neutrino flavor physics on the prospects for the synthesis of nuclei in these sites; (3) Understanding neutrino-nucleus interactions, nuclear partition functions, and weak strength distributions in high temperature environments; and (4) Assessing how uncertainties and new beyond-standard-model possibilities in the neutrino sector could impact ideas on nucleosynthesis, dark matter, compact object physics, and cosmology, with an eye toward finding constraints otherwise unobtainable in the laboratory.The research supported in this project will provide insights into how atomic nuclei and radiation behave in extreme conditions of temperature and density. In turn, these insights could give important clues about the nature of some elementary particles and the origin of the elements, for example, in the fiery interiors of supernova explosions, or at the time when the universe was only seconds old. These are fundamental questions that will provide unique opportunities for the training of young scientists, nuclear physicists, at both the graduate and undergraduate levels.