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

该项目支持的研究将为原子核、基本粒子和辐射在极端温度和密度条件下的行为提供洞察力。PI将利用这些洞察力来提供关于基本粒子的性质，特别是神秘的中微子，以及关于元素是如何在自然界中合成的重要线索，例如，在宇宙早期的最初几秒钟内，坍塌的恒星或碰撞的中子星的炽热内部中最重的元素，以及最轻的元素。反过来，这些考虑可以给我们对新物理学的洞察。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，磨练成能够对宇宙提供的极端环境中的中微子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中微子改变它们的味道(例如，电子型中微子变成tau型中微子，反之亦然)。这是一个严重的非线性问题，因为中微子的味道/自旋决定了中微子如何相互作用，而它们相互作用的方式又决定了味道/自旋的变化。为此，P.I.和他的研究生和本科生将致力于：(1)理解和模拟控制一般介质中中微子味道和自旋演化的量子动力学方程；(2)构建早期宇宙和致密天体环境中中微子味道/自旋演化的大规模数值模拟，并评估这种中微子味道物理对这些地点核合成前景的反馈，以及这一物理对多信使观测和暗扇区物理的影响；(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 extreme conditions of temperature and density. The PI will leverage 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, e.g., the heaviest elements in the fiery interiors of collapsing stars or colliding neutron stars, and the lightest in the first seconds in the early universe. In turn, these considerations can give us insight into new physics. 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 in the extreme environments provided by 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 neutrinos to change their flavors (e.g., electron type neutrinos changing to tau type and vice versa). This is a fiercely nonlinear problem because neutrino flavor/spin determines how neutrinos interact, and how they interact determines how flavors/spin change. To these ends, the P.I. and his graduate and undergraduate students will work toward: (1) Understanding and modeling the quantum kinetic equations which govern neutrino flavor and spin evolution in a general medium; (2) Constructing large-scale numerical simulations of neutrino flavor/spin evolution in the early universe and compact object environments and assessing the feedback of this neutrino flavor physics on the prospects for the synthesis of nuclei in these sites, and the implications of this physics for multi-messenger observations 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.