arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1208.4600astro-ph.COastro-ph.HEhep-ph
收藏

中微子在宇宙学距离上的衰变及其对中微子望远镜的意义

Neutrino Decays over Cosmological Distances and the Implications for Neutrino Telescopes

Philipp Baerwald, Mauricio Bustamante, Walter Winter

摘要:

通过求解衰变方程,讨论了超相对论中微子在宇宙学距离上的衰变。我们表明,有显着的概念差异相比,更简化的中微子衰变的治疗。例如,中微子的最大旅行距离受到哈勃长度的限制,这意味着通常认为更长的中微子寿命可以通过更长的距离来探测并不适用。因此,来自超新星1987 A的中微子寿命极限不能被高能天体物理中微子超过。我们讨论了中微子光谱和味比的影响,从伽马射线暴作为河外源的一个例子,使用最新的中微子通量预测。如果SN 1987 A的观测意味着ν_1是稳定的,而其他质量本征态的衰变速率远小于它们的当前边界,那么与冰立方最敏感的区域中的级联速率相比,μ子轨道速率可以被大大抑制。在这种情况下,没有伽马射线暴中微子可能会发现使用μ子轨道,即使与全尺寸的实验,而可靠的信息,高能天体物理源只能从级联测量。作为另一个结果,最近观察到的两个级联事件候选人在PeV的能量将不会伴随着相应的μ子轨道。

英文摘要:

We discuss decays of ultra-relativistic neutrinos over cosmological distances by solving the decay equation in terms of its redshift dependence. We demonstrate that there are significant conceptual differences compared to more simplified treatments of neutrino decay. For instance, the maximum distance the neutrinos have traveled is limited by the Hubble length, which means that the common belief that longer neutrino lifetimes can be probed by longer distances does not apply. As a consequence, the neutrino lifetime limit from supernova 1987A cannot be exceeded by high-energy astrophysical neutrinos. We discuss the implications for neutrino spectra and flavor ratios from gamma-ray bursts as one example of extragalactic sources, using up-to-date neutrino flux predictions. If the observation of SN 1987A implies that ν_1 is stable and the other mass eigenstates decay with rates much smaller than their current bounds, the muon track rate can be substantially suppressed compared to the cascade rate in the region IceCube is most sensitive to. In this scenario, no gamma-ray burst neutrinos may be found using muon tracks even with the full scale experiment, whereas reliable information on high-energy astrophysical sources can only be obtained from cascade measurements. As another consequence, the recently observed two cascade event candidates at PeV energies will not be accompanied by corresponding muon tracks.

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。

↑