WoU-MMA: Thermodynamics of Nuclei and Nuclear Matter

宇宙中重元素的起源仍然是个谜。据信，这些元素中至少有一半是在中子星之间的剧烈碰撞中产生的，这是否属实是核天体物理学的一个核心问题。为了回答这个问题，在天体物理学模拟中研究了中子-恒星碰撞，这反过来需要来自核物理学的输入数据。具体来说，模拟需要关于在非常高的温度和密度下的中子和质子的信息。该项目旨在从第一性原理计算此类热性质：从中子和质子及其相互作用开始，并实现晶格量子场论的计算机器。使用相同的工具，PI还将研究目前在全球许多实验室实现的超冷原子物理学中更简单的相关系统。PI将指导研究生从事这项研究的教学和培训合作与北卡罗来纳大学彭布罗克分校，并在研究合作与密歇根州立大学，华盛顿大学，和TU达姆施塔特。外联活动还将包括在联合国大学-CH举办第21届多体理论最新进展国际会议，最近对中子星星合并的引力波和电磁波探测为原子核和核物质热力学的从头定性提供了新的动力。后者需要作为动力学天体物理学模拟的输入，但提出了一个具有挑战性的量子多体问题。该项目的首要目标是面对这一挑战，从中子物质的有限温度热力学开始，使用非相对论晶格场论的从头算非微扰工具结合手性有效理论相互作用。该研究计划将侧重于核物质的热状态方程，从稀释的纯中子物质开始，计划在稍后阶段包括质子。对中子物质的配对、超流性和成团性质的计算也在计划中，因为它们会影响中子星的结构和热演化。该项目还将开展核子成团和有限核态密度的研究，以及中子皮的从头计算，所有这些都与核天体物理学和将在世界各地的重离子设施中实现的丰中子核物理学有关。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The origin of the heavy elements in our Universe remains a mystery. At least half of those elements are believed to be generated in violent collisions between neutron stars, and whether this is true is a central question in nuclear astrophysics. To answer that question, neutron-star collisions are studied in astrophysics simulations, which in turn need input data from nuclear physics. Specifically, simulations require information about neutrons and protons at very high temperatures and densities. This project aims to calculate such thermal properties from first principles: starting from neutrons and protons and their interactions, and implementing the computational machinery of lattice quantum field theory. Using the same tools, the PI will also study simpler, related systems in ultracold atomic physics that are currently realized in many laboratories worldwide. The PI will mentor graduate students engaged in this research in a teaching-and-training collaboration with UNC-Pembroke, and in research collaborations with Michigan State University, the University of Washington, and TU Darmstadt. Outreach activities will also include the organization of the 21st International Conference on Recent Progress in Many-Body Theories at UNC-CH.The recent gravitational- and electromagnetic-wave detection of neutron star mergers has given new impetus to the ab initio characterization of the thermodynamics of nuclei and nuclear matter. The latter are required as input to dynamical astrophysics simulations but pose a challenging quantum many-body problem. The overarching objective of this project is to face that challenge, starting with the finite-temperature thermodynamics of neutron matter, using the ab initio non-perturbative tools of non-relativistic lattice field theory combined with chiral effective theory interactions. The research program will focus on the thermal equation of state of nuclear matter, beginning with dilute pure neutron matter, with plans to include protons at a later stage. Calculations of the pairing, superfluidity, and clustering properties of neutron matter are also planned, as they impact the structure and thermal evolution of neutron stars. This project will also pursue studies of nucleon clustering and the density of states of finite nuclei, and ab initio calculations of the neutron skin, all of which are relevant to nuclear astrophysics and the physics of neutron-rich nuclei to be realized in heavy-ion facilities around the world.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.