arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.11659hep-exphysics.ins-det
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中子结构对中基线反应堆中微子振荡实验中中微子质量分级分辨的潜在影响

Potential impact of sub-structure on the resolution of neutrino mass hierarchy at medium-baseline reactor neutrino oscillation experiments

Zhaokan Cheng, Neill Raper, Wei Wang, Chan Fai Wong, Jingbo Zhang

摘要:

在过去的十年中,最新的中微子混合角$θ_{13}$的精确测量,使在中基线反应堆中微子振荡(MBRO)实验的中微子质量等级(MH)的分辨率。另一方面,最近对反应堆中微子通量的计算预测了由于β衰变中的库仑效应而导致的$\barν_e$谱中的π能级子结构。反应堆光谱中的这种精细结构可能是MBRO方法确定中微子MH的一个重要问题,因为它们可能影响用于区分不同层次的次主导振荡模式。不方便的是,目前反应堆实验的能量分辨率不足以测量这种精细结构,因此这些预测的不连续性的能量的大小和位置尚未得到实验证实。有人推测,需要一个近距离检测器,具有足够的能量分辨率来分辨精细结构,以便在任何试图区分MH的分析中都可以考虑到它。本文以大亚湾核电站的中微子能谱为参考,在预测反应堆中微子能谱的基础上,研究了精细结构对MH分辨力的影响。我们还研究了近探测器是否可以提高中微子MH分辨率的灵敏度,使用各种假设的近探测器能量分辨率。

英文摘要:

In the past decade, the precise measurement of the lastly known neutrino mixing angle $θ_{13}$ has enabled the resolution of neutrino mass hierarchy (MH) at medium-baseline reactor neutrino oscillation (MBRO) experiments. On the other hand, recent calculations of the reactor neutrino flux predict percent-level sub-structures in the $\barν_e$ spectrum due to Coulomb effects in beta decay. Such fine structure in the reactor spectrum could be an important issue for the determination of neutrino MH for the MBRO approach since they could affect the sub-dominant oscillation pattern used to discriminate different hierarchies. Inconveniently, the energy resolutions of current reactor experiments are not sufficient to measure such fine structure, and therefore the size and location in energy of these predicted discontinuities has not been confirmed experimentally. There has been speculation that a near detector is required with sufficient energy resolution to resolve the fine structure such that it can be accounted for in any analysis which attempts to discriminate the MH. This article studies the impact of fine structure on the resolution of MH, based on the predicted reactor neutrino spectra, using the measured spectrum from Daya Bay as a reference. We also investigate whether a near detector could improve the sensitivity of neutrino MH resolution using various assumptions of near detector energy resolution.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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