标题： π^+π^- 库仑相互作用研究及其在数据处理中的应用 显示英文标题

标题： The π^+π^- Coulomb interaction study and its use in the data processing

摘要： In this work the Coulomb effects (Coulomb correlations) in $\pi^+\pi^-$ pairs produced in p + Ni collisions at 24 GeV/$c$, are studied using experimental $\pi^+\pi^-$ pair distributions in $Q$, the relative momentum in the pair center of mass system (c.m.s), and its projections $Q_L$ (longitudinal component) and $Q_t$ (transverse component) relative to the pair direction in the laboratory system (l.s.). $Q$、$Q_L$和$Q_t$分布在质心系中的{\sl 库仑对}已经被模拟，假设它们由已知点状库仑关联函数$A_C(Q)$所修改的相空间描述，考虑了由于非点状对产生和强两π介子相互作用带来的小效应。 {\sl 非库仑对}的相同分布根据相空间进行了模拟，但不包含$A_C(Q)$。 结果显示，在所有$Q_t$区间中，包括小$Q_t$（小开口角$\theta$在 l.s. 中）的{\sl 库仑对}数量，其理论精度优于 2%。 在小$Q_t$下模拟和实验的{\sl 库仑对}数量的比较，使我们能够检查并校正小$\theta$（0.06 mrad 及以下）的符合对的探测效率。 证明了{\sl 库仑对}可以作为新的物理工具来检查和校正模拟事件的质量。 {\sl 库仑对}的特殊性质是能够检查和校正探测效率，特别是对于开口角度较小的粒子对。 显示英文摘要

摘要： In this work the Coulomb effects (Coulomb correlations) in $\pi^+\pi^-$ pairs produced in p + Ni collisions at 24 GeV/$c$, are studied using experimental $\pi^+\pi^-$ pair distributions in $Q$, the relative momentum in the pair center of mass system (c.m.s), and its projections $Q_L$ (longitudinal component) and $Q_t$ (transverse component) relative to the pair direction in the laboratory system (l.s.). The $Q$, $Q_L$, and $Q_t$ distributions of the {\sl Coulomb pairs} in the c.m.s. have been simulated assuming they are described by the phase space modified by the known point-like Coulomb correlation function $A_C(Q)$, corrected for small effects due to the nonpoint-like pair production and the strong two-pion interaction. The same distributions of {\sl non-Coulomb pairs} have been simulated according to the phase space, but without $A_C(Q)$. It is shown that the number of {\sl Coulomb pairs} in all $Q_t$ intervals, including the small $Q_t$ (small opening angles $\theta$ in the l.s.) is calculated with the theoretical precision better than 2\%. The comparison of the simulated and experimental numbers of {\sl Coulomb pairs} at small $Q_t$ allows us to check and correct the detection efficiency for the pairs with small $\theta$ (0.06 mrad and smaller). It is shown that {\sl Coulomb pairs} can be used as a new physical tool to check and correct the quality of the simulated events. The special property of the {\sl Coulomb pairs} is the possibility of checking and correcting the detection efficiency, especially for the pairs with small opening angles.