Developing the MeV potential of DUNE: Detailed considerations of muon-induced spallation and other backgrounds
Developing the MeV potential of DUNE: Detailed considerations of muon-induced spallation and other backgrounds
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DOI：
10.1103/physrevc.99.055810
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发表时间：
2018-11
影响因子：
3.1
通讯作者：
G. Zhu;S. Li;J. Beacom
中科院分区：
文献类型：
--
作者：
G. Zhu;S. Li;J. Beacom
深地下中微子实验（DUNE）可能是革命性的MeV中微子天体物理学，由于其巨大的探测器体积，独特的事件重建能力，以及出色的灵敏度的$\nu_e$味。然而，其背景尚不清楚。一个主要的背景是由于氩的μ子散射，它产生不稳定的同位素，后来β衰变。我们提出了第一个全面的研究MeV的spectrometry背景氩，详细说明同位素生产机制和衰变特性，分析β能量和时间分布，并提出实验削减。我们发现，在5兆电子伏的标称检测阈值以上，最重要的背景是-令人惊讶的-由于低A同位素，如Li，Be和B，即使高A同位素附近的氩大量产生。我们表明，spiritual背景可以有力地拒绝简单的削减，有明确的改进路径。我们将这些背景速率与DUNE中可能的MeV天体物理中微子信号速率进行比较，包括太阳中微子（在配套论文arXiv：1808.08232中详细介绍），超新星爆发中微子和弥漫超新星中微子背景。此外，为了帮助触发策略，我们量化了单个和多个兆电子伏事件的速率，由于溅射，放射性中子捕获和其他背景，包括通过堆积。我们的总体结论是，DUNE具有MeV中微子天体物理学的高潜力，但达到这种潜力需要新的实验举措。
The Deep Underground Neutrino Experiment (DUNE) could be revolutionary for MeV neutrino astrophysics, due to its huge detector volume, unique event reconstruction capabilities, and excellent sensitivity to the $\nu_e$ flavor. However, its backgrounds are not yet known. A major background is expected due to muon spallation of argon, which produces unstable isotopes that later beta decay. We present the first comprehensive study of MeV spallation backgrounds in argon, detailing isotope production mechanisms and decay properties, analyzing beta energy and time distributions, and proposing experimental cuts. We show that above a nominal detection threshold of 5 MeV, the most important backgrounds are --- surprisingly --- due to low-A isotopes, such as Li, Be, and B, even though high-A isotopes near argon are abundantly produced. We show that spallation backgrounds can be powerfully rejected by simple cuts, with clear paths for improvements. We compare these background rates to rates of possible MeV astrophysical neutrino signals in DUNE, including solar neutrinos (detailed in a companion paper arXiv:1808.08232), supernova burst neutrinos, and the diffuse supernova neutrino background. Further, to aid trigger strategies, we quantify the rates of single and multiple MeV events due to spallation, radiogenic neutron capture, and other backgrounds, including through pileup. Our overall conclusion is that DUNE has high potential for MeV neutrino astrophysics, but reaching this potential requires new experimental initiatives.