Can one observe Earth matter effects with supernova neutrinos
Can one observe Earth matter effects with supernova neutrinos
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DOI：
10.1103/physrevd.86.083004
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发表时间：
2012-07
影响因子：
5
通讯作者：
E. Borriello;S. Chakraborty;A. Mirizzi;P. Serpico;I. Tamborra
中科院分区：
文献类型：
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作者：
E. Borriello;S. Chakraborty;A. Mirizzi;P. Serpico;I. Tamborra
地球物质中的中微子振荡可能在超新星中微子谱中引入特殊的调制。这种效应的检测已被提议作为诊断工具的中微子质量等级在“大”1-3轻子混合角θ 1-3。我们对下一代大型地下探测器（即，0.4吨水切伦科夫，50千吨闪烁和100千吨液体氩探测器）的基础上，中微子通量从国家的最先进的SN模拟。最近的模拟预测的平均能量低于先前的预期，并出现了一种趋势，在SN冷却阶段的不同口味的中微子通量的均衡。因此，地球物质效应的检测应该比以前的研究所预期的更具挑战性。特别是，对于一个典型的银河SN在10千秒差距，没有一个建议的探测器可能能够检测到地球调制的SN中微子信号。由于中微子（相对于反中微子）能量和通量的较大差异，在100 kton液态氩探测器中，地球效应在几kpc处就可以观察到。只有非常接近的恒星，可以在SNe（如参宿四在0.2千秒差距）中演化，所有三个探测器都可以清楚地看到地球的信号。最后，以冰立方作为共同探测器，与Mton水切伦科夫探测器一起监测地球效应，它无法探测到任何银河系超新星的SN中微子事件率的任何相当大的变化。
Neutrino oscillations in the Earth matter may introduce peculiar modulations in the supernova (SN) neutrino spectra. The detection of this effect has been proposed as diagnostic tool for the neutrino mass hierarchy at "large" 1-3 leptonic mixing angle theta13. We perform an updated study on the observability of this effect at large next-generation underground detectors (i.e., 0.4 Mton water Cherenkov, 50 kton scintillation and 100 kton liquid Argon detectors) based on neutrino fluxes from state-of-the-art SN simulations. The average energies predicted by recent simulations are lower than previously expected and a tendency towards the equalization of the neutrino fluxes of the different flavors during the SN cooling phase appears. As a consequence, the detection of the Earth matter effect should be more challenging than expected from previous studies. In particular, for a typical galactic SN at 10 kpc, none of the proposed detectors may be able to detect the Earth modulation in the SN neutrino signal. Due to larger differences in neutrino (as opposed to antineutrino) energies and fluxes, in a 100 kton liquid Argon detector the Earth effect becomes observable at few kpc. Only for very close-by stars, that could evolve in SNe (like Betelgeuse at 0.2 kpc) all three detectors would clearly see the Earth signature. Finally, taking Icecube as co-detector together with a Mton water Cherenkov detector to monitor the Earth effect, it is not able to detect any sizable variation in the SN neutrino event rate for any galactic supernova.