Atomic nucleus is a quantum many-body system consisting of protons and neutrons. Nevertheless, it is known that their characteristics can be well described and understood by the few-body picture. One of such pictures is the single-particle motion of a nucleon in a mean-field potential made by all nucleons. Another one is the clustering phenomenon, \(\alpha \) clustering for example, in which a nucleus is divided into two or more clusters coupling weakly like molecules.One of the powerful probes for such states of a nucleus is the nucleon and cluster knockout reactions. In this paper, the distorted wave impulse approximation (DWIA) framework is briefly reviewed as one of the reaction theories which describes the knockout reaction. Its benchmark comparison with other reaction theories is also discussed. The application of the DWIA framework to the nucleon knockout reaction analysis from medium-mass neutron-rich nuclei driven by the RIKEN SEASTAR project is shown. As for the \(\alpha \) knockout reaction, recent progress in reproduction of the \(\alpha \) knockout reaction data from \(^{20}\)Ne is reviewed and the surface sensitivity of the reaction is discussed. The first direct evidence of the \(\alpha \) particle formation on the surface of medium mass nuclei and its isotope dependence is also introduced. Finally, the summary and perspectives of the particle knockout reactions are given.

原子核是一个由质子和中子组成的量子多体系统。尽管如此，众所周知，它们的特征可以通过少体图很好地描述和理解。其中一张图片是一个核子在所有核子产生的平均场势中的单粒子运动。另一种是聚类现象，\(\alpha \)例如，聚类，其中一个原子核被分成两个或多个团簇，它们像分子一样弱耦合。对原子核这种状态的一种强有力的探针是核子和簇敲除反应。在本文中，扭曲波脉冲近似（DWIA）框架作为描述敲除反应的反应理论之一进行了简要回顾。还讨论了它与其他反应理论的基准比较。展示了 DWIA 框架在 RIKEN SEASTAR 项目驱动的中等质量富中子核的核子敲除反应分析中的应用。至于\(\alpha \)敲除反应，从\(^{20}\)复制\(\alpha \)敲除反应数据的最新进展回顾了 Ne 并讨论了反应的表面敏感性。还介绍了在中等质量原子核表面形成\(\alpha \)粒子及其同位素依赖性的第一个直接证据。最后，给出了粒子敲除反应的总结和展望。