核子-核子相互作用（核力）是原子核结构研究的重要基础。随着第一性原理计算在原子核物理领域的迅猛发展，除了大家熟知的两体核力之外，三体核力乃至多体核力的效应也引起广泛关注。本项目结合国内外研究现状以及申请人已有的工作基础，研究现实核力中Delta共振态自由度引起的三体力效应，内容主要包括：发展pi介子与核子赝矢耦合的现实核力，系统的研究现实核力中，pi介子与核子赝标耦合与赝矢耦合方式对原子核结构基本性质的影响；发展包含有Delta共振态的现实核力，通过第一性原理计算，系统的研究Delta共振态产生的三体力效应，并分析其微观机制。通过本项目的研究，进一步完善高精度的现实核子-核子相互作用，改善第一性原理计算对于原子核多体问题的描述，深入探索现实核力对原子核结构性质的影响。

The nucleon-nucleon (NN) interaction is the foundation of the nuclear structure study. With the prompt development of the ab initio calculation in nuclear physics, the three-body force and many-body force has aroused wide concern besides the realistic two-body force. Based on the current research status and also the applicants’ achievements and expertise, the present project is proposed to investigate three-body effect from the degree of freedom of Delta-isobar excitation in two-body force. The main topics include: 1) the construction of realistic NN interaction with the pseudo-vector coupling of pion and nucleon, and the systematic study of the effects of pseudo-scalar coupling and pseudo-vector coupling in realistic NN interaction on the ground state properties of nuclear structure; 2) the construction of the realistic NN interaction with Delta isobars, and the systematic study of the three-body force effect from Delta isobars in ab initio calculation and the corresponding microscopic mechanism. This project is aiming at an improved high-precision realistic NN interaction, the better description of nuclear many-body problem with ab initio calculation and further insight into the influence of realistic NN interaction on the properties of nuclear structure.