JUNO实验中大气中微子的物理研究

At the beginning of 2013，the Jiangmen Underground Neutrino Observatory (JUNO) has been approved by the Chinese Academy of Sciences as a "Strategic leading science and technology projects" with a budget of 2 billion￥. It is found that the JUNO experiment can identify the neutrino mass hierarchy through detecting the low energy (1.8-10MeV) reactor anti-electron neutrinos. In this project, we will focus on the neglected middle-high energy (0.1-10GeV) atmospheric neutrino physics. The latest research result shows that the liquid scintillator (LS) detector can reconstruct the direction of the charged lepton from the neutrino charged current interaction. Based on this result and many advantages of LS detector technology (excellent energy resolution, very low energy threshold and perfect slow neutron detection ability), we shall investigate the physics related to atmospheric neutrino oscillation, which includes the measurement of neutrino oscillation parameters (neutrino mass hierarchy, Dirac CP violation phase and the octant of atmospheric mixing angle), the experimental test of new physical models (neutrino non-standard interactions, Lorentz violation and CPT violation in the atmospheric neutrino oscillation) and the dark matter indirect search. In addition, we will also study and develop the immature event reconstruction and particle identification techniques those are key abilities for the JUNO's physics analysis. The theoretical results of this project will be very helpful for us to increase the JUNO confidence in neutrino mass hierarchy and find new physics beyond the standard model. For the event reconstruction and particle identification, we will get some innovative results those are very important for the JUNO's detection ability and the future LS experiments. We believe that this project will greatly expand the JUNO's research range and scientific significance.

鉴于江门中微子实验（JUNO）已经被国家批准建设，本项目将研究方向放在与JUNO直接相关的未被重视的大气中微子物理领域。最新研究表明液闪探测器除了具有优秀的能量分辨率还可以重建大气中微子的方向。因此本项目将依据JUNO液闪探测器的特点来研究与大气中微子振荡相关的物理，包括中微子振荡参数(质量顺序、CP破坏相位和大气混合角的象限)的测量能力和一些中微子新物理模型（非标准相互作用、洛伦兹破坏和CPT破坏等）的实验检验以及暗物质的间接探测。我们也将研究和发展远未成熟的与大气中微子事例相关的事例重建和粒子鉴别算法。本项目的理论成果将有助于提高JUNO对质量顺序等振荡参数的测量能力和发现超出标准模型的新物理；我们在事例重建方面的研究将会得到一些创新性的技术成果，这无论对于JUNO测量能力的提高还是未来相关实验的物理研究都是非常重要的。本项目的顺利开展将大大拓宽JUNO的研究范围和科学意义。

鉴于江门中微子实验（JUNO）已经被国家批准建设，本项目依据JUNO液闪探测器的特点研究了JUNO实验对大气中微子及相关物理的测量能力。经过4年的研究，本项目在利用大气中微子测量中微子振荡参数、寻找与大气中微子相关的新物理（质子衰变）、探测暗物质湮灭产生的中微子信号、液闪探测器的事例重建和粒子鉴别技术等方面都取得了预期的成果。此外，我们建立了一个基于GENIE和NuWro两个产生子的大气中微子数据库。这些研究成果为JUNO未来的物理研究打下了坚实的基础，同时也大大拓宽了JUNO的研究范围和科学意义。