原子核物理的核心课题和重要挑战之一，是基于真实的核子之间相互作用，对实验室和宇宙演化中产生的核素进行统一的描述。基于当前国内外第一性原理研究的现状，以及申请人前期研究中发现的问题和不足，本项目拟发展和完善能够自洽处理原子核三体力的第一性原理蒙特卡罗壳模型。项目将采用手征核力N3LO的两体和N2LO的三体相互作用，发展包含三体关联的幺正关联算符方法和Hubbard-Stratonovich变换，发展与当前超级计算机匹配的数值计算程序。通过蒙特卡罗模拟和能量甄别筛选出重要的基矢，极大降低模型空间维度，从而能够系统地、精确地对中等质量原子核进行第一性原理描述。项目将定量分析三体力对原子核特别是奇特核性质的影响，重点研究三体力在结合能、能级顺序、滴线核位置、壳结构演化等方面所起的作用。项目不仅能为实验对三体力的探索提供理论参考，亦能为手征有效场论构建真实核力的研究提供核结构数据支撑和模型检验。

One of the key topics and central challenges of nuclear physics is to develop a unified description of all nuclei created in the laboratory and the cosmos based on the underlying forces between nucleons. In view of the present situation of the first-principles study in China and abroad, as well as the problems and shortcomings found in the earlier studies of the applicant, the project is intended to develop and improve a nuclear ab initio Monte Carlo shell model, with which the nuclear three-body forces can be treated in a self-consistent way. The project will use the two-body forces in the chiral force N3LO and the three-body forces in N2LO. It will develop a unitary correlation operator method and a Hubbard-Stratonovich transform involving the three-body correlations, and to develop a numerical calculation program that matches the current supercomputer. The important basis vectors can be selected through the Monte Carlo simulation and energy screening. The dimension of the model space is reduced greatly so that the nuclei in the medium mass range can be investigated systematically and precisely from the first principle. The project will quantitatively analyze the effect of the three-body forces on the nuclei, especially the exotic nuclei, and focus on the role of the three-body forces in the binding energy, the order of the energy level, the position of the drip line, and the evolution of the shell structure etc. The project not only provides theoretical reference for the experiment to explore the nuclear three-body forces, but also can provide the data support and model test for the construction of the realistic nuclear force for the effective field theory.