Quantum Monte Carlo Calculations of Nucleon Systems

我们宇宙中的许多核过程都发生在超新星和中子星的极端条件下。在这些条件下，原子核和核物质的性质很难或不可能在实验室中重现，必须从理论上计算。这些数据对于理解天体物理学中重要的系统和过程是必要的，比如富中子物质、中子星、超新星、r过程核合成和中微子散射。在这个项目中开发的量子多粒子方法在物理学的许多领域都有广泛的应用。这些包括与项目直接相关的核物理方面，冷原子气体研究和电子结构。以前在这个项目中开发的方法已经应用于这些领域。该项目将培训本科生和研究生，让他们参加国家和国际会议，并传播研究结果。该项目将继续开发和使用精确的技术来计算原子核和核物质的性质，使用量子蒙特卡罗方法，即大量量子自由度的随机抽样方法。主要目的是发展辅助场量子蒙特卡罗方法，以采样具有核相互作用所有重要部分的原子核中质子和中子的空间和自旋同位旋自由度。这包括自旋轨道和三体相互作用。人们正在开发新的波函数，可以有效地对原子核进行评估，以获得中大型和富中子原子核的准确性质。超流动性在中子星物质中有重要的影响。研究者和他的学生将使用同样的方法来研究核系统和冷原子气体中的相关现象。许多在原子核和核物质中重要的配对和超流体机制可以在这些系统中进行研究和验证，在这些系统中可以使用桌面实验装置进行详细的实验测量。

Many nuclear processes in our universe occur under extreme conditions in supernovae and neutron stars. The properties of nuclei and nuclear matter under these conditions, which are difficult or impossible to reproduce in the laboratory, must necessarily be calculated theoretically. These data are needed to understand astrophysically important systems and processes such as neutron rich matter, neutron stars, supernovae, and r-process nucleosynthesis and neutrino scattering. The quantum many-particle methods developed within this project have broad applications across many areas of physics. These include the nuclear physics aspects directly relating to the project, cold atomic gas research, and electronic structure. Methods previously developed within this project have been applied in each of these areas. The project will train both undergraduate and graduate students, give them exposure at national and international conferences, and provide for dissemination of the results.This project will continue work developing and using accurate techniques to calculate the properties of nuclei and nuclear matter using quantum Monte Carlo methods, i.e. stochastic sampling methods for the large number of quantum degrees of freedom. A primary aim is to develop auxiliary field quantum Monte Carlo methods to sample both the space and spin-isospin degrees of freedom of protons and neutrons in nuclei with all important parts of the nuclear interaction. These include both the spin-orbit and three-body interactions. New wave functions which can be efficiently evaluated for nuclei are being developed, with the goal of obtaining accurate properties for medium to large and neutron rich nuclei. Superfluidity has major consequences in neutron star matter. The investigator and his students will use the same methods to study both the nuclear systems and the related phenomena in cold atomic gases. Many of the pairing and superfluid mechanisms important in nuclei and nuclear matter can be studied and verified in these systems where detailed experimental measurements can be made using table-top experimental setups.