Directional statistics for realistic weakly interacting massive particle direct detection experiments
Directional statistics for realistic weakly interacting massive particle direct detection experiments
复制标题
现实弱相互作用大粒子直接探测实验的方向统计
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
N. Spooner
中科院分区：
文献类型：
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作者：
Ben Morgan;A. Green;N. Spooner
在弱相互作用大质量粒子（WIMP）直接探测实验中，事件率的方向依赖性为区分WIMP事件和潜在背景提供了有力工具。我们使用多种（非参数）统计检验来研究，当在预期信号的计算中纳入核反冲方向重建的不确定性时，区分WIMP信号和各向同性背景所需的事件数量。我们考虑了一系列银河系晕的模型，还研究了旨在探测银河系晕的非球形性/各向同性的旋转对称性检验。最后，我们研究了探测WIMP潮汐流的方法。我们发现，如果知道反冲的方向，那么对于所考虑的所有晕模型，大约十个事件就足以区分WIMP信号和各向同性背景，反冲方向重建的不确定性只会略微增加所需的事件数量。如果不知道反冲的方向，所需的事件数量要大一个数量级，不同晕模型之间差异很大，并且反冲分辨率现在是一个重要因素。旋转对称性检验需要大约一千个事件才能区分球形晕和明显的三轴晕，然而，无论是否知道反冲的方向，大约一百个事件就可以检测到由于潮汐流导致的峰值反冲方向与太阳运动方向的偏离。
The direction dependence of the event rate in WIMP direct detection experiments provides a powerful tool for distinguishing WIMP events from potential backgrounds. We use a variety of (nonparametric) statistical tests to examine the number of events required to distinguish a WIMP signal from an isotropic background when the uncertainty in the reconstruction of the nuclear recoil direction is included in the calculation of the expected signal. We consider a range of models for the Milky Way halo, and also study rotational symmetry tests aimed at detecting nonsphericity/isotropy of the Milky Way halo. Finally we examine ways of detecting tidal streams of WIMPs. We find that if the senses of the recoils are known then of order ten events will be sufficient to distinguish a WIMP signal from an isotropic background for all of the halo models considered, with the uncertainties in reconstructing the recoil direction only mildly increasing the required number of events. If the senses of the recoils are not known the number of events required is an order of magnitude larger, with a large variation between halo models, and the recoil resolution is now an important factor. The rotational symmetry tests require of order a thousand eventsmore » to distinguish between spherical and significantly triaxial halos, however a deviation of the peak recoil direction from the direction of the solar motion due to a tidal stream could be detected with of order a hundred events, regardless of whether the sense of the recoils is known.« less