论文标题
标量和费米二号simp simp暗物质，带有偶然的$ \ mathbb {z}^{} _ 4 $ symmetry
Scalar and Fermion Two-component SIMP Dark Matter with an Accidental $\mathbb{Z}^{}_4$ Symmetry
论文作者
论文摘要
在本文中，我们首次构建了两个组件强烈相互作用的大型颗粒（SIMP）暗物质（DM）模型，其中复杂的标量和类似矢量的费米子起着SIMP DM候选物的作用。这两个粒子由于意外的$ \ mathbb {z}^{} _ 4 $对称性而稳定，$ \ text {u}（1）^{} _ \ textsf {d} $ gauge对称。通过在SIMP粒子之间引入一个额外的复杂标量作为中介器，该模型可以具有确定DM Relic密度的$ 3 \ 2 $过程。另一方面，SIMP DM颗粒可以通过热浴保持动力学平衡，直到通过$ \ text {u}（1）（1）^{} _ \ textsf {d} $ gauge耦合到DM冻结温度。最重要的是，我们发现不可避免的两循环诱导的$ 2 \ 2 $流程紧密连接到$ 3 \ 2 $过程，该过程将在DM化学冻结后重新分布SIMP DM数量密度。此外，与其他SIMP模型相比，这种重新分布将显着修改DM的自相互作用横截面的预测。至关重要的是要包括两循环诱导的$ 2 \ 2 $ nil灭，以获得正确的DM现象学。
In this paper, we construct for the first time a two-component strongly interacting massive particles (SIMP) dark matter (DM) model, where a complex scalar and a vector-like fermion play the role of the SIMP DM candidates. These two particles are stable due to an accidental $\mathbb{Z}^{}_4$ symmetry after the breaking of a $\text{U}(1)^{}_\textsf{D}$ gauge symmetry. By introducing one extra complex scalar as a mediator between the SIMP particles, this model can have $3 \to 2$ processes that determine the DM relic density. On the other hand, the SIMP DM particles can maintain kinetic equilibrium with the thermal bath until the DM freeze-out temperature via the $\text{U}(1)^{}_\textsf{D}$ gauge couplings. Most importantly, we find an unavoidable two-loop induced $2 \to 2$ process tightly connecting to the $3 \to 2$ process that would redistribute the SIMP DM number densities after the chemical freeze-out of DM. Moreover, this redistribution would significantly modify the predictions of the self-interacting cross section of DM compared with other SIMP models. It is crucial to include the two-loop induced $2 \to 2$ annihilations to obtain the correct DM phenomenology.
