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

该项目支持的研究将提供对原子核、基本粒子和辐射在宇宙中发现的极端温度和密度条件下的行为的洞察。这项研究将试图利用这些洞察力，为基本粒子的性质，特别是神秘的中微子，以及元素在自然界中是如何合成的提供重要线索，例如，在宇宙历史上最初几秒钟内，坍塌或碰撞的中子星燃烧的内部中最重的元素，以及最轻的元素。反过来，这些考虑可能会产生关于新物理学的线索，这些线索可能会补充从地球实验中收集到的见解。这个项目中将要进行的计算将涉及将人类的基本自然理论，即量子力学，磨练成一个能够对宇宙极端环境中的中微子和原子核的行为进行建模的工具。该项目的另一个关键成果将是培训年轻的核物理学家，包括研究生和本科生。该项目支持的研究将致力于探索中微子和原子核的基本物理，一方面利用核物理和中微子物理令人兴奋的新发展的交集，另一方面利用多信使天文学和精密宇宙学的出现带来的新数据和见解的爆炸性增长。这个项目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这些粒子改变它们的味道(例如，电子型中微子变成tau型中微子，反之亦然)。这可能是一个严重的非线性问题，因为中微子成分的味道含量在一定程度上决定了中微子味道的变化！这个项目的研究目标是(1)了解和模拟非线性中微子演化，并评估这一过程对致密天体(塌缩恒星核；合并双中子星)动力学和核合成的影响；(2)利用这些和其他考虑因素的见解，将我们对致密天体环境和早期宇宙的模型和观测约束转化为对超越标准模型物理、暗物质和暗扇区物理的洞察；(3)了解高温环境中的原子核结构、中微子-原子核相互作用、原子核配分函数和原子核的弱强度分布。该项目提出了未来NSF投资的十大想法之一的“宇宙之窗：多信使天体物理时代”的目标。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The research supported in this Project will provide insights into how atomic nuclei and elementary particles and radiation behave in the conditions of extreme temperature and density found in the cosmos. This research will seek to use these insights to provide important clues about the nature of elementary particles, the mysterious neutrinos in particular, and about how the elements are synthesized in nature, for example, the heaviest elements in the fiery interiors of collapsing stars or colliding neutron stars, and the lightest in the first seconds in the history of the universe. In turn, these considerations could yield clues about new physics, clues that may complement insights gleaned from terrestrial experiments. The calculations to be done in this project will involve honing humanity's fundamental theory of nature, i.e., Quantum Mechanics, into a tool capable of modeling the behavior of neutrinos and atomic nuclei in the extreme environments of the cosmos. Another key product of this Project will be the training of young nuclear physicists, at both the graduate and undergraduate levels. The research supported in this Project will be directed toward probing 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, with the explosion of new data and insights from the advent of multi-messenger astronomy and precision 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 these particles to change their flavors (e.g., electron type neutrinos changing to tau type and vice versa). This can be a fiercely nonlinear problem because the flavor content of the neutrino component in part determines how neutrino flavors change! Research in this project will target (1) Understanding and modeling nonlinear neutrino flavor evolution and assessing the impact of this process on compact objects (collapsing stellar cores; merging binary neutron stars) dynamics and nucleosynthesis; (2) Using the insights from these and other considerations to turn our models of, and observational constraints on compact object environments and the early universe into insights into beyond standard model physics, dark matter, and dark sector physics; (3) Understanding nuclear structure, neutrino-nucleus interactions, nuclear partition functions, and nuclear weak strength distributions in high temperature environments.This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.