Combined sensitivity to the neutrino mass ordering with JUNO, the IceCube Upgrade, and PINGU
Combined sensitivity to the neutrino mass ordering with JUNO, the IceCube Upgrade, and PINGU
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DOI：
10.1103/physrevd.101.032006
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发表时间：
2020-02-21
影响因子：
5
通讯作者：
Cabrera, A.
中科院分区：
文献类型：
--
作者：
Aartsen, M. G.;Ackermann, M.;Cabrera, A.
中微子质量本征态的有序性是中微子物理学中的一个基本问题。虽然目前的中微子振荡实验能够对这种排序产生适度的指示，但下一代即将进行的实验旨在提供确凿的证据。在本文中，我们研究了两个未来的多用途中微子振荡实验JUNO和冰立方升级，这两个非常不同的和互补的路线走向中微子质量排序的综合性能。20 kt中基线反应堆中微子实验JUNO所采用的方法包括仔细研究10个核反应堆堆芯产生的振荡（nu）对棒（e）的能谱。另一方面，IceCube升级由部署在IceCube DeepCore中心的七个额外的密集仪器弦组成，将观测大量受到地球物质影响的振荡的大气中微子。在两种方法的联合拟合中，在错误的质量排序内，在它们的优选质量平方差Δ m（31）（2）= m（3）（2）- m（1）（2）之间发生张力。在JUNO和IceCube升级的情况下，这允许在3-7年的时间尺度上排除> 5 sigma的错误排序-即使在对实验个体敏感性不利的情况下。对于PINGU，一个26串探测器阵列，被设计为IceCube的潜在低能扩展，在联合分析中，可以在1.5年内排除反向排序（正常排序为3年）。
The ordering of the neutrino mass eigenstates is one of the fundamental open questions in neutrino physics. While current-generation neutrino oscillation experiments are able to produce moderate indications on this ordering, upcoming experiments of the next generation aim to provide conclusive evidence. In this paper we study the combined performance of the two future multi-purpose neutrino oscillation experiments JUNO and the IceCube Upgrade, which employ two very distinct and complementary routes toward the neutrino mass ordering. The approach pursued by the 20 kt medium-baseline reactor neutrino experiment JUNO consists of a careful investigation of the energy spectrum of oscillated (nu) over bar (e) produced by ten nuclear reactor cores. The IceCube Upgrade, on the other hand, which consists of seven additional densely instrumented strings deployed in the center of IceCube DeepCore, will observe large numbers of atmospheric neutrinos that have undergone oscillations affected by Earth matter. In a joint fit with both approaches, tension occurs between their preferred mass-squared differences Delta m(31)(2) = m(3)(2) - m(1)(2) in within the wrong mass ordering. In the case of JUNO and the IceCube Upgrade, this allows to exclude the wrong ordering at > 5 sigma on a timescale of 3-7 years-even under circumstances that are unfavorable to the experiments individual sensitivities. For PINGU, a 26-string detector array designed as a potential low-energy extension to IceCube, the inverted ordering could be excluded within 1.5 years (3 years for the normal ordering) in a joint analysis.