论文标题
$ u（1）_ {b-l} $ SM的扩展
Two component FIMP DM in a $U(1)_{B-L}$ extension of the SM
论文作者
论文摘要
在这项工作中，我们在流行的$ B-L $扩展标准模型（SM）中讨论了两个组成部分的费米FIMP暗物质（DM）。由于引入了$ \ mathbb {z} _ {2} $离散对称性，因此kev sm量规单程费米昂是稳定的，可以是温暖的DM候选者。另外，这个$ \ mathbb {z} _ {2} $对称性可以通过选择相应的Yukawa耦合来成为长寿或稳定的粒子，这有助于最轻的右中微子，质量为GEV，成为一个长寿或稳定的粒子。首先，在没有GEV DM分量的情况下（即，没有调整其相应的Yukawa耦合），我们仅将KEV DM视为由Freeze-In机构产生的单个组件DM。其次，我们研究了两个组件FIBM DM方案，并强调可以在广泛的参数空间中实现正确的球形DM遗物密度。
In this work, we discuss two component fermionic FIMP dark matter (DM) in a popular $B-L$ extension of the standard model (SM) with inverse seesaw mechanism. Due to the introduced $\mathbb{Z}_{2}$ discrete symmetry, a keV SM gauge singlet fermion is stable and can be a warm DM candidate. Also, this $\mathbb{Z}_{2}$ symmetry helps the lightest right-handed neutrino, with mass of order GeV, to be a long-lived or stable particle by choosing a corresponding Yukawa coupling to be very small. Firstly, in the absence of a GeV DM component (i.e., without tuning its corresponding Yukawa coupling), we consider only a keV DM as a single component DM produced by the freeze-in mechanism. Secondly, we study a two component FIMP DM scenario and emphasize that the correct ballpark DM relic density bound can be achieved for a wide parameter space.
