标题： 介子原子中等轴矢量$πN$幅度的重整化 显示英文标题

标题： Renormalization of the isovector $πN$ amplitude in pionic atoms

摘要： 从介子原子中提取等矢量s波πN振幅的研究，特别强调了不确定性及其对核中中子密度分布假设和所用数据集大小的依赖性。 只有对介子原子数据的“全局”分析才能揭示出提取的等矢量s波πN振幅b_1=-0.108\pm 0.007 m_\pi ^{-1}与自由πN对应的b_1^{免费}=-0.0885^{+0.0010}_{-0.0021} m_\pi ^{-1}之间的差异，其中在误差分析中包含了中子密度的不确定性。 “深结合”π介子原子态的作用被讨论，这些态无法提供新信息的原因也被解释。 显示英文摘要

摘要： The extraction of the isovector s-wave pi N amplitude from pionic atoms is studied with special emphasis on uncertainties and their dependence on the assumptions made regarding the neutron density distributions in nuclei and on the size of the data base used . Only `global' analyses of pionic-atom data reveal a discrepancy between the extracted isovector s-wave pi N amplitude b_1=-0.108\pm0.007 m_\pi^{-1} and its free pi N counterpart b_1^{free}=-0.0885^{+0.0010}_{-0.0021} m_\pi ^{-1}, where the uncertainty in the neutron densities is included in the error analysis. The role of `deeply bound' pionic atom states is discussed and the reason for failure of these states to provide new information is explained.