发表机构
East Texas A&M University; Technische Universität Darmstadt; ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH（东德克萨斯农工大学; 达姆施塔特工业大学; 极端物质研究所EMMI，GSI重离子研究中心有限公司）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文综述了通过单双核子敲出反应诊断不稳定核中各类核子关联的理论框架，涵盖谱因子、程函近似等关键方法，并探讨了单粒子强度降低问题及其对反应模型的依赖。
AI 中文摘要
我们回顾了从快速弹体上移除一个和两个核子、准自由质子诱导反应如$(p,2p)$和$(p,pn)$，以及利用独占动量和符合观测量来诊断关联所依据的物理思想和反应理论。特别强调了独立粒子占据数、长程集体关联和对关联、张量驱动的中子-质子关联，以及由核相互作用的排斥芯和非中心分量产生的短程关联之间的区别。讨论发展了重叠函数语言、谱因子、程函剥离和衍射、扭曲波冲量近似、因子化和谱函数、质心和反冲效应、双核子振幅、对密度，以及测量截面与从头算或壳模型结构之间的关系。实验单粒子强度相对于简单壳模型预期的众所周知的降低、其对分离能不对称性的依赖，以及关于反应模型系统学的持续争论均被详细处理。
英文摘要
We review the physical ideas and reaction theory underlying one- and two-nucleon removal from fast projectiles, quasi-free proton-induced reactions such as $(p,2p)$ and $(p,pn)$, and the use of exclusive momentum and coincidence observables to diagnose correlations. Particular emphasis is placed on the distinction between independent-particle occupancy, long-range collective and pairing correlations, tensor-driven neutron-proton correlations, and short-range correlations generated by the repulsive core and noncentral components of the nuclear interaction. The discussion develops the overlap-function language, spectroscopic factors, eikonal stripping and diffraction, distorted-wave impulse approximation, factorization and spectral functions, center-of-mass and recoil effects, two-nucleon amplitudes, pair densities, and the relation between measured cross sections and ab initio or shell-model structure. The well-known reduction of experimental single-particle strength relative to simple shell-model expectations, its dependence on separation-energy asymmetry, and the continuing debate over reaction-model systematics are treated in detail.
Comments15 pages. Oxford Research Encyclopedia of Physics (2006)
