Time delay and resonances in potential scattering
Time delay and resonances in potential scattering
复制标题
势散射中的时间延迟和共振
DOI：
10.1088/0305-4470/39/29/016
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
K B Sinha
中科院分区：
文献类型：
--
作者：
W. Amrein;K B Sinha
我们呈现固定时间延迟算子的静止表达式，其痕量在量子机械电位散射中电位总散射横截面和壳时间延迟操作员的痕迹具有分析性扩展到复杂的能量，最多在通常的共振极处（分析持续的S-matrix的极点）在下半部和处他们的镜像相对于真实的轴结果证实了共振应通过散射横截面中的峰和较大（虽然为正）延迟的峰值出现的想法。
We present stationary expressions for the on-shell time delay operator and for its trace in quantum-mechanical potential scattering. The trace of this operator is shown to represent the time delay for a monoenergetic and well-collimated beam of initial states. For exponentially decaying potentials the total scattering cross section and the trace of the on-shell time delay operator have analytic extensions to complex energies, with poles at most at the usual resonance poles (poles of the analytically continued S-matrix) in the lower half plane and at their mirror images with respect to the real axis. At real energies close to such a pole both the scattering cross section and the time delay are approximately of Breit–Wigner type, the sign of the time delay being related to that of the virial. These results corroborate the idea that a resonance should show up through a peak in the scattering cross section and a large (though positive) time delay.