Abstract We re-examine the longstanding disagreement between the SIMPLE and PICASSO superheated liquid-based dark matter search projects regarding discrimination between neutron- and α-induced bubble nucleation events, and its dependence on the distribution of liquid droplet sizes. A simple analysis based on (1) the interaction of α and neutrons with the detector droplet size distribution, combined with (2) the acoustics of the subsequent bubble expansion, reproduces the observations of each experiment under the reported measurement conditions. The differences in discrimination efficiency between the two experiments are shown to result from the relation between the droplet size distributions and the minimum α penetration distances in the liquid necessary to achieve the critical linear energy transfer necessary for bubble nucleation, the number of proto-bubbles generated in the transfer, and the subsequent bubble evolution. The results remove the tension between the SIMPLE and PICASSO experiments with respect to particle discrimination.

中文翻译：

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解决 SIMPLE 和 PICASSO 暗物质项目之间粒子鉴别的张力

摘要 我们重新审视了 SIMPLE 和 PICASSO 基于过热液体的暗物质搜索项目之间关于区分中子和 α 诱导气泡成核事件及其对液滴尺寸分布的依赖性的长期分歧。基于 (1) α 和中子与探测器液滴尺寸分布的相互作用的简单分析，结合 (2) 随后气泡膨胀的声学，再现了在报告的测量条件下每个实验的观察结果。两个实验之间鉴别效率的差异是由液滴尺寸分布和液体中实现气泡成核所需的临界线性能量转移所需的最小 α 穿透距离之间的关系引起的，转移中产生的原始气泡的数量，以及随后的气泡演化。结果消除了 SIMPLE 和 PICASSO 实验之间在粒子辨别方面的张力。