Abstract This work explains a delayed-coincidence method to perform MeV-scale neutrino spectroscopy with electron-neutrino capture on gallium. An electron-neutrino possessing energy greater than 407.6 keV can be captured on gallium and produce a daughter germanium nucleus at its first excited state with a mean lifetime of 114 ns. The released electron and gammas before the first excited state of Ge can generate a prompt signal representing the solar neutrino energy and the gamma from the deexcitation of the first excited state, 175 keV, can give a delayed signal. The cross-section of this electron-neutrino capture process is evaluated and is comparable with electron-neutrino capture on chlorine. A possible implementation with a liquid scintillator is discussed to exploit the delayed coincidence. The detection scheme is more feasible than using 115In, etc., but need a larger target. The proposed method can be helpful for the MeV-scale solar neutrino spectroscopy and for solving the gallium anomaly.

中文翻译：

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用于中微子光谱的镓电子-中微子捕获延迟巧合

摘要 这项工作解释了一种延迟符合方法，用于在镓上进行电子中微子捕获的 MeV 级中微子光谱。能量大于 407.6 keV 的电子-中微子可以被镓捕获并在其第一激发态产生子锗核，平均寿命为 114 ns。Ge 第一激发态之前释放的电子和伽马可以产生代表太阳中微子能量的瞬发信号，第一激发态去激发的伽马 175 keV 可以给出延迟信号。该电子-中微子捕获过程的横截面经过评估，可与对氯的电子-中微子捕获进行比较。讨论了使用液体闪烁体的可能实施方式以利用延迟符合。该检测方案比使用115In等更可行，但需要更大的目标。所提出的方法有助于 MeV 尺度的太阳中微子光谱和解决镓异常。