论文标题
区分狄拉克与主要中微子：宇宙学探测
Distinguishing Dirac vs. Majorana Neutrinos: a Cosmological Probe
论文作者
论文摘要
宇宙背景中微子（$c_νb）$螺旋成分对于狄拉克或majorana中微子而言是不同的，基于$c_νb$捕获对中微子的性质敏感的探测器。我们首次计算中微子穿越暗物质场的螺旋性变化，以定量计算这种对捕获率的影响。我们表明，一小部分中微子改变了它们的螺旋性，而不管它们被空隙或暗物质光环偏转。 GPC $^3 $中100个最大的空隙或光晕的平均信号给出了一个预测，如果中微子是Dirac，在地球上测得的$C_νB$背景的密度应为48 cm $ {^{^{ - 3}} $，左helialical Neutrinos，减少15％（53.6 cm $ $}}^^^^^^^^^^^^^^^^^^^^^5％; （无效）关于标准计算，而不包括大规模结构引起的重力效应。就100 g tritium探测器的总捕获率而言，这将以$ 4.9^{+1.1} _ { - 0.8} _ { - 0.8} $中微子的中微子在迪拉克情况下，作为未知中微子质量量表的函数，或者如果中子为大型中微子，则每年8.1个。因此，尽管对于非权利主义情况而言，尽管要小于两个因子，但它仍然足够大，可以被检测到，并且突出了未来$C_νB$检测器的功能，作为中微子双β衰减实验的替代方法，以发现中微性的性质。
Cosmic background neutrinos ($C_νB)$ helicity composition is different for Dirac or Majorana neutrinos making detectors based on $C_νB$ capture sensitive to the nature of neutrinos. We calculate, for the first time, the helicity changes of neutrinos crossing dark matter fields, to quantitatively calculate this effect on the capture rate. We show that a fraction of neutrinos change their helicity, regardless of them being deflected by a void or a dark matter halo. The average signal from the 100 most massive voids or halos in a Gpc$^3$ gives a prediction that if neutrinos are Dirac, the density of the $C_ν B$ background measured on Earth should be 48 cm${^{-3}}$ for left-helical neutrinos, a decrease of 15% (53.6 cm${^{-3}}$; 5%) for a halo (void) with respect to the standard calculation without including gravitational effects due to large scale structures. In terms of the total capture rate in a 100 g tritium detector, this translates in $4.9^{+1.1}_{-0.8}$ neutrinos per year for the Dirac case, as a function of the unknown neutrino mass scale, or 8.1 per year if neutrinos are Majorana. Thus although smaller than the factor two for the non-relativistic case, it is still large enough to be detected and it highlights the power of future $C_ν B$ detectors, as an alternative to neutrinoless double beta decay experiments, to discover the neutrino nature.
