Collaborative Research: Continuation of the Dark Matter Search with XENON1T at LNGS

多项天文观测已经确定，宇宙中大约85%的物质不是由正常原子组成的，而是不发射或吸收光的未被检测到的基本“暗物质”粒子。破译这种所谓的暗物质的性质对宇宙学、天体物理学和高能粒子物理学具有根本的重要性。一个主要的假设是，它是由弱相互作用大质量粒子（WIMP）组成的，这些粒子是在大爆炸后产生的。如果WIMP是暗物质，那么它们在我们星系中的存在可能是通过位于地下深处的探测器中的原子核散射来检测的，以帮助排除宇宙射线造成的背景。对WIMP暗物质的直接探测将解决粒子物理学和宇宙学中的一个基本谜团，为了解宇宙的主要物质组成和粒子物理学标准模型之外的物理学提供了一个独特的窗口。该奖项支持了在INFN Gran Sasso国家实验室（LNGS）地下实验室参与XENON 1 T暗物质搜索计划的美国团体。XENON项目继续吸引公众的想象力。例如，几个电视节目，如“生活大爆炸”，就证明了这一点，其中有几个节目介绍了氙的情节和结果。通过讲座和外联活动鼓励公众对科学的兴趣。XENON 1 T将在解决暗物质之谜方面发挥重要作用，无论是探测WIMP，还是将它们作为可行的暗物质候选者置于巨大的压力之下。在解决这个基本的物理学问题，这些奖项将吸引许多本科生和研究生以及博士后研究人员，让他们接触到物理学和宇宙学的各种学科，并培训他们最先进的技术，从而准备成为该领域的未来领导者。最后，XENON中使用的仪器和技术与广泛的应用有关，从国土安全和医学成像领域到大型数据集的分析和统计处理。未来四年的计划将集中在XENON 1 T实验的持续运行及其科学数据分析上。由130名科学家组成的国际XENON合作继续由哥伦比亚大学的PI领导，美国成员在实验管理及其科学计划方面发挥关键作用。XENON 1 T使用了迄今为止建造的最大的液体氙时间投影室（TPC），有2吨的活动靶，对暗物质弱相互作用大质量粒子（WIMP）的灵敏度最高，对于40 GeV的WIMP，灵敏度为2 × 10^-47 cm ^2。有了这项提案的资助，美国将在十年结束后继续领导直接寻找暗物质。

Multiple astronomical observations have established that about 85% of the matter in the universe is not made of normal atoms, but must be otherwise undetected elementary "dark matter" particles that do not emit or absorb light. Deciphering the nature of this so-called Dark Matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. A leading hypothesis is that it is comprised of Weakly Interacting Massive Particles, or WIMPs, that were produced moments after the Big Bang. If WIMPs are the dark matter, then their presence in our galaxy may be detectable via scattering from atomic nuclei in detectors located deep underground to help reject backgrounds due to cosmic rays. Direct detection of WIMP dark matter would solve a fundamental mystery in particle physics and cosmology, providing a unique window to learning about the primary matter constituent of the Universe and of physics beyond the Standard Model of particle physics. This award supports the US groups involved in the XENON1T dark matter search program at the INFN Gran Sasso National Laboratory (LNGS) underground laboratory.The XENON project continues to captivate the imagination of the public. This is evidenced, for example, by several TV shows such as "The Big Bang Theory", which on several occasions featured XENON plots and results. Public interest in science is encouraged through talks and outreach activities. XENON1T will play a significant role in solving the dark matter puzzle, by either detecting WIMPs, or putting them under immense pressure as viable dark matter candidates. In addressing this fundamental physics problem, these awards will engage many undergraduate and graduate students as well as post-doctoral researchers, exposing them to a variety of subjects in physics and cosmology, and training them in state-of-the-art technologies, thus preparing to become future leaders in the field. Finally, the instrumentation and techniques used in XENON are relevant to a wide range of applications, from areas in homeland security and medical imaging, to the analysis and statistical treatment of large data sets.The program for the next four years will focus on the continued operation of the XENON1T experiment and its science data analysis. The international XENON Collaboration of 130 scientists continues to be led by the PI at Columbia University with key roles served by US members both in the management of the experiment and its scientific program. XENON1T uses the largest liquid xenon time projection chamber (TPC) built to-date, with 2 tonnes active Xe target, and the highest sensitivity to dark matter Weakly Interacting Massive Particles (WIMPs), at the level of 2 × 10^-47 cm^2 for 40 GeV WIMPs. With funding of this proposal, the US will remain in the lead of the direct search for dark matter well beyond the end of the decade.