Visible sterile neutrinos as the earliest relic probes of cosmology
Visible sterile neutrinos as the earliest relic probes of cosmology
复制标题
DOI：
10.1016/j.physletb.2019.135113
复制
发表时间：
2019-09
影响因子：
4.4
通讯作者：
G. Gelmini;P. Lu;V. Takhistov
中科院分区：
文献类型：
--
作者：
G. Gelmini;P. Lu;V. Takhistov
实验室对无菌中微子的探测可以提供宇宙在大爆炸核合成（BBN）之前演化的第一个迹象，这是一个尚未测试的时代。这种“可见的”无菌中微子在即将进行的实验中可以观察到，例如KATRIN/TRISTAN和HUNTER在keV质量范围内，PINEMY和其他在eV质量范围内的实验。在宇宙的温度达到5 MeV之前，宇宙学通常会做出一系列标准假设。然而，基于替代假设的非标准前BBN宇宙学可能会出现在有动机的理论模型中，并且同样与所有现有数据一致。我们重新审视生产无菌中微子的质量为0.01 eV至1兆电子伏的两个例子，这样的模型：标量张量和低再加热温度预BBN宇宙学。在这两种情况下，假定的3.5 keV X射线信号线对应于一个无菌中微子，其混合量足以在即将到来的实验室实验中进行测试。此外，活跃-无菌中微子混合的宇宙学/天体物理学上限明显弱于标准的前BBN宇宙学，这表明这些限制并不稳健。例如，在标量张量情况下，LSND和MiniBooNE短基线以及DANSS和近地天体反应堆实验所暗示的潜在信号区域完全不受宇宙学限制的约束。我们的工作突出表明，不育中微子可能构成前BBN时代的敏感探针。
A laboratory detection of a sterile neutrino could provide the first indication of the evolution of the Universe before Big-Bang Nucleosynthesis (BBN), an epoch yet untested. Such “visible” sterile neutrinos are observable in upcoming experiments such as KATRIN/TRISTAN and HUNTER in the keV mass range and PTOLEMY and others in the eV mass range. A set of standard assumptions is typically made about cosmology before the temperature of the Universe was 5 MeV. However, non-standard pre-BBN cosmologies based on alternative assumptions could arise in motivated theoretical models and are equally in agreement with all existing data. We revisit the production of sterile neutrinos of mass 0.01 eV to 1 MeV in two examples of such models: scalar-tensor and low reheating temperature pre-BBN cosmologies. In both of them, the putative 3.5 keV X-ray signal line corresponds to a sterile neutrino with a mixing large enough to be tested in upcoming laboratory experiments. Additionally, the cosmological/astrophysical upper limits on active-sterile neutrino mixings are significantly weaker than in the standard pre-BBN cosmology, which shows that these limits are not robust. For example, in the scalar-tensor case the potential signal regions implied by the LSND and MiniBooNE short-baseline as well as the DANSS and NEOS reactor experiments are entirely not bound by cosmological restrictions. Our work highlights that sterile neutrinos may constitute a sensitive probe of the pre-BBN epoch.