We consider neutrino oscillations in vacuum in the framework of quantum field theory in which neutrino production and detection processes are part of a single Feynman diagram and the corresponding cross section is computed in the standard way, i.e. with final states represented by plane waves. We use assumptions which are realized in actual experiments and concentrate on the detection process. Moreover, we also allow for a finite time interval of length τ during which the detector records neutrino events. In this context we are motivated by accelerator-neutrino oscillation experiments where data taking is synchronized in time with the proton spill time of the accelerator. Given the final momenta and the direction of neutrino propagation, we find that in the oscillation amplitude—for all practical purposes—the neutrino energy Q is fixed, apart from an interval of order 2 π ℏ/ τ around a mean energy ##IMG## [http://ej.iop.o...] {$\bar{Q};$}

中文翻译：

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重温真空中微子振荡的量子场论

我们在量子场论的框架下考虑真空中的中微子振荡，在该理论中，中微子的产生和检测过程是单个费曼图的一部分，并且以标准方式计算相应的横截面，即最终状态由平面波表示。我们使用在实际实验中实现的假设，并专注于检测过程。此外，我们还允许在长度为τ的有限时间间隔内检测器记录中微子事件。在这种情况下，我们受到加速器-中微子振荡实验的启发，在该实验中，数据获取与加速器的质子溢出时间在时间​​上同步。给定最终动量和中微子的传播方向，我们发现在所有实际目的的振荡振幅中，中微子能量Q是固定的，