论文标题
不对称的SIMP暗物质模型
An Asymmetric SIMP Dark Matter Model
论文作者
论文摘要
在本文中，我们构建了第一个不对称的强烈相互作用的巨大颗粒（SIMP）暗物质（DM）模型，其中具有非零化学势的新型矢量样费米子和新的复合体标量都可以是不对称的DM颗粒。在自发断裂u（1）$^{} _ \ textsf {d} $暗规对称性之后，这两个粒子可以具有意外的$ \ mathbb {z}^{}^{} _ 4 $电荷使它们稳定。通过在SIMP DM之间添加一个更复杂的标量作为中介，DM的遗物密度由$ 3 \至2 $确定，在此模型中，$ 2 \ twop诱导的$ 2 \ to $ 2 \至2 $ nihihitations。另一方面，SIMP DM可以与热浴保持动力学平衡，直到通过新的仪表相互作用进行DM冷冻温度。有趣的是，该模型可能会对DM产生弹跳效应，从而在DM冻结DM之后，DM数密度上升。通过这种效果，该模型中DM自相互作用横截面的预测可能与天体物理观测一致，并且可以通过原始不对称来解释DM能量密度与重型物质能量密度的比率。我们还预测了可在未来的预测实验中用于测试该模型的DM电子弹性散射横截面。
In this paper, we construct the first asymmetric strongly interacting massive particles (SIMP) dark matter (DM) model, where a new vector-like fermion and a new complex scalar both having nonzero chemical potentials can be asymmetric DM particles. After the spontaneous breaking of a U(1)$^{}_\textsf{D}$ dark gauge symmetry, these two particles can have accidental $\mathbb{Z}^{}_4$ charges making them stable. By adding one more complex scalar as a mediator between the SIMP DM, the relic density of DM is determined by $3 \to 2$ and two-loop induced $2 \to 2$ annihilations in this model. On the other hand, the SIMP DM can maintain kinetic equilibrium with the thermal bath until the DM freeze-out temperature via the new gauge interaction. Interestingly, this model can have a bouncing effect on DM, whereby the DM number density rises after the chemical freeze-out of DM. With this effect, the prediction of the DM self-interacting cross section in this model can be consistent with astrophysical observations, and the ratio of the DM energy density to the baryonic matter energy density can be explained by primordial asymmetries. We also predict the DM-electron elastic scattering cross section that can be used to test this model in future projected experiments.
