标题： 迷你BooNE异常，Ds介子衰变到mu+nu和重态中微子 显示英文标题

标题： The MiniBooNE anomaly, the decay Ds -> mu+nu and heavy sterile neutrino

摘要： 最近有建议认为，MiniBooNE实验观察到的低能电子样事件异常过剩，可能可以通过一个质量约为500 MeV的重惰性中微子nu_h的辐射衰变来解释，其μ子混合强度在|U_{\mu h}|^2 \simeq (1-4)\times 10^{-3}的范围内。如果这样的nu_h存在，它在Ds -> mu+nu衰变中的混合会导致Ds -> mu+nu_h衰变，分支比为\simeq (1.2-5.5)\times 10^{-4}，这处于实验可探测范围内。有趣的是，以这种水平存在的Ds -> mu+nu_h衰变也可能解释为什么目前测量的Ds -> mu+nu衰变率略高于理论预测值。这增强了对该衰变模式进行灵敏搜索的动机，并使其成为探测惰性-活性中微子混合的中微子实验的有趣且互补的补充。以CLEO-c实验为例，我们建议通过对现有数据的分析来搜索Ds -> mu+nu_h衰变。还简要讨论了Ds -> tau+nu衰变的测量与理论描述之间的差异。 显示英文摘要

摘要： It has been recently suggested that the anomalous excess of low-energy electron-like events observed by the MiniBooNE experiment, could be explained by the radiative decay of a heavy sterile neutrino nu_h of the mass around 500 MeV with a muonic mixing strength in the range |U_{\mu h}|^2 \simeq (1-4)\times 10^{-3}. If such nu_h exists its admixtures in the decay Ds -> mu+nu would result in the decay Ds -> mu+nu_h with the branching fraction \simeq (1.2-5.5)\times 10^{-4}, which is in the experimentally accessible range. Interestingly, the existence of the Ds -> mu+nu_h decay at this level may also explain why the currently measured decay rate of Ds -> mu+nu is slightly higher than the predicted one. This enhances motivation for a sensitive search for this decay mode and makes it interesting and complementary to neutrino experiments probing sterile-active neutrino mixing. Considering, as an example the CLEO-c experiment, we suggest to perform a search for the decay Ds -> mu+nu_h with the analysis of existing data. The discrepancy between the measurements and theoretical description of the decay Ds -> tau+nu is also discussed in brief.