Journal Article

Scalar and fermion two-component SIMP dark matter with an accidental ℤ4 symmetry

Ho, Shu-Yu, Lu, Chih-Ting, Ko, Pyungwon

2022

Overview

A bstract 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 ℤ 4 symmetry after the breaking of a U(1) D gauge symmetry. By introducing one extra complex scalar as a mediator between the SIMP particles, this model can have 3 → 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 U(1) D gauge couplings. Most importantly, we find an unavoidable two-loop induced 2 → 2 process tightly connecting to the 3 → 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 → 2 annihilations to obtain the correct DM phenomenology.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V,SpringerOpen
• Subject: Classical and Quantum Gravitation / Couplings / Dark matter / Early Universe Particle Physics / Elementary Particles / Fermions / High energy physics / Models for Dark Matter / New Gauge Interactions / Particle Nature of Dark Matter / Phenomenology / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Quantum Physics / Regular Article - Theoretical Physics / Relativity Theory / String Theory / Symmetry / Thermal baths