论文标题
建议：JSNS $^2 $ -II
Proposal: JSNS$^2$-II
论文作者
论文摘要
本文介绍了J-PARC材料和生命科学实验设施（MLF）的JSNS $^2 $ -II实验的目标和预期灵敏度。 The JSNS$^2$-II experiment is the second phase of the JSNS$^2$ experiment (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) with two detectors which are located in 24 m (an existing detector) and 48 m (new one) baselines to improve the sensitivity of the search for sterile neutrinos, especially in the low $Δm^2$ region, which has been indicated by the外观模式的全局拟合。新的第二个检测器的结构与现有的JSNS $^2 $检测器相似，该检测器已经在起作用。为了补偿由于距汞目标距离而导致的中微子通量的减少，GD负载的液体闪烁体的靶质量是丙烯酸容器内的线性烷基苯基（LAB）基于线性烷基苯（LAB）的液体闪烁体为35吨。为了保持检测器与第一个检测器相同的光覆盖，我们将以240 PMT的范围围绕丙烯酸容器。通过这种实验设置和5年（乘以1 MW梁功率）的暴露，与当前的JSNS $^2 $相比，JSNS $^2 $ -II的灵敏度显着提高，尤其是在低$Δm^2 $振荡参数区域。 JSNS $^2 $ -II还可以确认或反驳以前具有3个Sigma C.l的实验首选的振荡参数的空间。考虑到这些情况和无菌中微子搜索的全球状态，我们渴望开始使用2023的两个检测器配置来构建第二个检测器。
This article describes the goal and expected sensitivity of the JSNS$^2$-II experiment at J-PARC Materials and Life Science Experimental Facility (MLF). The JSNS$^2$-II experiment is the second phase of the JSNS$^2$ experiment (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) with two detectors which are located in 24 m (an existing detector) and 48 m (new one) baselines to improve the sensitivity of the search for sterile neutrinos, especially in the low $Δm^2$ region, which has been indicated by the global fit of the appearance mode. The new second detector has a similar structure as the existing JSNS$^2$ detector, which is already working. To compensate for the reduction of the neutrino flux due to the distance from the mercury target, the target mass of the Gd-loaded liquid scintillator which is the Linear AlkylBenzene (LAB) based liquid scintillator inside the acrylic vessel is 35 tons. To keep the same photo-coverage of the detector as the first detector, we will surround the acrylic vessel with 240 PMTs. With this experimental setup and 5 years (times 1 MW beam power) exposure, the sensitivity of the JSNS$^2$-II is significantly improved compared to the current JSNS$^2$, especially in the low $Δm^2$ oscillation parameter region. The JSNS$^2$-II can also confirm or refute the most of the oscillation parameters' space preferred by the previous experiments with 3 sigma C.L.. Considering these situations and world wide status of the sterile neutrino searches, we are eager to start the data taking with the two detector configuration from 2023. The fund to build the second detector was already secured.
