标题： 测量宇宙中微子背景的各向异性 显示英文标题

标题： Measuring Anisotropies in the Cosmic Neutrino Background

摘要： 中微子捕获在氚上已成为探测宇宙中微子背景（CvB）的一种有前景的方法。 我们表明，当它们的自旋矢量与氚核的极化轴反向对齐，并且它们沿极化方向接近时，遗迹中微子最容易被捕获。 因此，CvB观测站可以通过极化氚目标来测量宇宙中微子速度和自旋分布中的各向异性。 由于实验室框架相对于宇宙框架的特殊速度以及晚期的引力效应，预计CvB中会出现一个小的偶极各向异性。 PTOLEMY实验，一个目前正在建设中的氚观测站，应该会观测到几乎各向同性的背景。 这将作为对潜在信号宇宙起源的有力检验。 极化靶测量还可以限制非标准中微子相互作用，这些相互作用会产生更大的各向异性，并有助于区分马约拉纳中微子与狄拉克中微子。 显示英文摘要

摘要： Neutrino capture on tritium has emerged as a promising method for detecting the cosmic neutrino background (CvB). We show that relic neutrinos are captured most readily when their spin vectors are anti-aligned with the polarization axis of the tritium nuclei and when they approach along the direction of polarization. As a result, CvB observatories may measure anisotropies in the cosmic neutrino velocity and spin distributions by polarizing the tritium targets. A small dipole anisotropy in the CvB is expected due to the peculiar velocity of the lab frame with respect to the cosmic frame and due to late-time gravitational effects. The PTOLEMY experiment, a tritium observatory currently under construction, should observe a nearly isotropic background. This would serve as a strong test of the cosmological origin of a potential signal. The polarized-target measurements may also constrain non-standard neutrino interactions that would induce larger anisotropies and help discriminate between Majorana versus Dirac neutrinos.