Precision Neutrino Oscillation Physics with JUNO

中微子是最普遍、最耐人寻味的基本粒子之一。它们不带电荷，与自然界其他基本粒子的相互作用非常弱。长期以来，它们也被认为是无质量的。然而，大约20年前，我们对中微子的理解发生了一场革命，发现这些难以捉摸的粒子在太空中旅行时，会改变它们的量子属性，即所谓的味道。这一现象通常被称为中微子振荡，现在被大量数据证实，并暗示中微子肯定有质量，即使质量很小。该奖项支持加州大学欧文分校(UCI)江门地下中微子天文台(JUNO)小组的活动。朱诺实验的主要目的是提供对中国、泰山和阳江核电站反应堆中产生的中微子相互作用的精确测量。UCI Juno团队将为实验的小型光电倍增管(PMT)系统的安装和调试做出关键贡献，并将领导对整个探测器的能量响应进行校准。该小组还在为新探测器的第一次振荡参数测量准备数据分析。该计划重新启动了加州大学洛杉矶分校的QuarkNet中心，包括一个专注于朱诺实验的大师班，主要目标是为高中教师和他们的学生提供粒子物理研究的机会，特别关注代表不足的群体的参与者。JUNO目前正在中国东南部建设中，旨在提供中微子质量状态有序性的首次测量。探测器计划于2022年开始采集数据。UCI Juno小组是该项目小型(3英寸)PMT系统的领导者，该系统由25,600个光电探测器组成。与激光定标系统相结合，小型光电倍增管系统是实现全JUNO探测器在1 MeV下3%的能量响应所必需的，并成为第一个同时观察“快”(第一和第三本征态)和“慢”(第一和第二本征态)振荡频率的实验。此外，达到探测器设计能量响应将有可能测量由第二和第三本征态的质量分裂驱动的振荡周期，从而在6年的数据获取后以大约3西格玛的速度区分两种质量排序方案。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Neutrinos are among the most ubiquitous and intriguing of the fundamental elementary particles. They have no electric charge and interact only very weakly with the other fundamental particles of nature. They were also long thought to be massless. However, a revolution in our understanding of neutrinos occurred roughly two decades ago with the discovery that these elusive particles change their quantum property known as flavor as they travel through space. This phenomenon, commonly referred to as neutrino oscillation, is now confirmed by a wealth of data and implies that the neutrino must have a mass, even if very small. This award supports the activities of the Jiangmen Underground Neutrino Observatory (JUNO) group at the University of California-Irvine (UCI). The JUNO experiment is primarily designed to provide precision measurements of the interactions of neutrinos produced in reactors at the China Taishan and Yangjiang nuclear power plants. The UCI JUNO team will provide key contributions to the installation and commissioning of the experiment’s small photomultiplier tube (PMT) system and will lead the calibration of the energy response of the full detector. The team is also preparing the data analyses for the first oscillation parameter measurements of the new detector. The program reinitiates the UCI QuarkNet center, including a Masterclass focused on the JUNO experiment, with a primary goal of providing opportunities in particle physics research to high-school teachers and their students with a particular focus on participants from underrepresented groups.JUNO is currently under construction in the southeast of China and is designed to provide a first measurement of the ordering of the neutrino mass states. The detector is scheduled to begin data taking in 2022. The UCI JUNO group is a leader in the project’s small (3-inch) PMT system, consisting of 25,600 photodetectors. Combined with the laser calibration system, the small PMT system is essential to realizing an energy response of the full JUNO detector of 3 percent at 1 MeV and become the first experiment to observe the effect of the “fast” (first and third eigenstates) and “slow” (first and second eigenstates) oscillation frequencies simultaneously. In addition, reaching the detector design energy response will make it possible to measure the oscillation cycles driven by the mass splitting of the second and third eigenstates, and thus discriminate between the two mass ordering scenarios at approximately 3 sigma after 6 years of data taking.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.