Space-time approach to scattering from many-body systems
Space-time approach to scattering from many-body systems
复制标题
多体系统散射的时空方法
DOI：
10.1103/physreva.58.280
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发表时间：
1997
影响因子：
2.9
通讯作者：
Robert Golub
中科院分区：
文献类型：
--
作者：
R. Gähler;J. Felber;F. Mezei;Robert Golub
我们从一个新的角度提出了许多身体系统的散射。代替基于平面波的通常的van Hove处理（适用于使用光子和大质量粒子的广泛散射过程），我们计算散射振幅作为散射样本上的时空积分，以入射波的相关函数为特征，这是由仪器形成的波场的结果。仪器的分辨率效应-由于仪器不同臂的路径差异导致的相关性损失被自动包括在内，并获得了不同仪器的分辨率函数的解析形式。与仪器的不同元素相关联的移动相关体积（相关函数显著的那些区域）的交集决定了可以在样品中观察到的最大相关长度（次数），从而决定了测量的动量（能量）分辨率。这幅由我们的技术导出的移动相关体的几何图显示了散射体与仪器形成的波场在空间和时间上是如何相互作用的。匹配相关体积以最大化交集区域产生一种透明的、图形化的仪器设计方法。pac: 03.65。Nk, 3.80 +r, 03.75, 61.12
We present scattering from many body systems in a new light. In place of the usual van Hove treatment, (applicable to a wide range of scattering processes using both photons and massive particles) based on plane waves, we calculate the scattering amplitude as a space-time integral over the scattering sample for an incident wave characterized by its correlation function which results from the shaping of the wave field by the apparatus. Instrument resolution effects - seen as due to the loss of correlation caused by the path differences in the different arms of the instrument are automatically included and analytic forms of the resolution function for different instruments are obtained. The intersection of the moving correlation volumes (those regions where the correlation functions are significant) associated with the different elements of the apparatus determines the maximum correlation lengths (times) that can be observed in a sample, and hence, the momentum (energy) resolution of the measurement. This geometrical picture of moving correlation volumes derived by our technique shows how the interaction of the scatterer with the wave field shaped by the apparatus proceeds in space and time. Matching of the correlation volumes so as to maximize the intersection region yields a transparent, graphical method of instrument design. PACS: 03.65.Nk, 3.80 +r, 03.75, 61.12.B