Experimental Particle Cosmology at Case

大量的观测表明，宇宙是由96%看不见的物质和能量组成的。不可见“暗物质”的主要候选者是大爆炸遗留下来的亚原子粒子，被称为弱相互作用大质量粒子（WIMP）。如果wimp存在，它们也是我们银河系的主要质量。虽然它们很少与常规物质相互作用，但它们应该可以被地球上足够灵敏的探测器探测到，通过它们与目标原子核的直接相互作用和随后的反冲。探测的主要挑战是将自然和宇宙产生的放射性降低10个数量级。该奖项将为凯斯小组在LUX（大型地下氙）暗物质实验上的工作提供基础支持。LUX的特点是一个300公斤重的两相氙暗物质探测器，它将被安置在位于南达科他州霍姆斯特克矿桑福德实验室戴维斯洞穴的一个大型水盾中。LUX目前正在开始对探测器进行最后的集成。LUX实验的重点是基于现有技术的可扩展设计，并将很快部署一个探测器，其WIMP灵敏度比目前公布的最佳极限高出近2个数量级。该小组在LUX的设计和建设中发挥了核心作用，并将在LUX的运营和分析中发挥重要作用。在更广泛的影响中，粒子暗物质的探测将改变和扩展粒子物理学和天文学界的世界活动。这项技术可以应用于其他基础实验，如双β衰变和太阳中微子，并可能产生新的医疗诊断技术，或应用于国土安全和核控制。该小组将参与与桑福德实验室联合开展的广泛的教育和推广活动。

A wealth of observations shows that the universe is composed of 96% invisible matter and energy. The leading candidate for the invisible "dark matter" is a subatomic particle left over from the big bang known as the Weakly Interacting Massive Particle (WIMP). If WIMPs exist, they are also the dominant mass in our own Milky Way. Although they very rarely interact with conventional matter, they should nonetheless be detectable by sufficiently sensitive detectors on Earth, through their direct interaction with, and the ensuing recoil of, nuclei in a target. The primary detection challenge is reducing natural and cosmogenic radioactivity by 10 orders of magnitude.This award will provide base support for the Case group for work on the LUX (Large Underground Xenon) dark matter experiment. LUX features a 300 kg two-phase xenon dark matter detector, which will be housed in a large water shield located in the Davis Cavern at the Sanford Lab in the Homestake Mine, South Dakota. LUX is currently beginning their final integration of the detector. The LUX experiment has focused on a scalable design based on existing technologies, and will soon field a detector with nearly 2 orders of magnitude better WIMP sensitivity than the best published limits. This group has had a central role in the design and construction of LUX, and will play a major role in LUX operations and analysis. Among Broader Impacts, the detection of particle dark matter would transform and extend world activities in the particle physics and astronomical communities. The technology can be applied to other fundamental experiments such as double beta decay and solar neutrinos, and may give rise to new medical diagnostic techniques, or applications to Homeland Security and nuclear control. This group will participate in extensive education and outreach activities being undertaken in conjunction with Sanford Lab.