Reshuffled strongly interacting massive particle dark matter

In this work, we reanalyze the multi-component strongly interacting massive particle (mSIMP) scenario using an effective operator approach. As in the single-component SIMP case, the total relic abundance of mSIMP dark matter (DM) is determined by the coupling strengths of 3 -> 2 processes achieved by a five-point effective operator. Intriguingly, we notice that there is an irreducible 2 -> 2 process induced by the corresponding five-point interaction in the dark sector, which would reshuffle the mass densities of SIMP DM after the chemical freeze-out. We dub this DM scenario as reshuffled SIMP (rSIMP). Given this observation, we then numerically solve the coupled Boltzmann equations including the 3 & RARR; 2 and 2 -> 2 processes to get the correct yields of rSIMP DM. It turns out that the masses of rSIMP DM must be nearly degenerate for them to contribute sizeable abundances. On the other hand, we also introduce effective operators to bridge the dark sector and visible sector via a vector portal coupling. Notably, we find that the reshuffled mechanism in the rSIMP scenario is sensitive to the size of the DM self-interacting cross section. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this work, the multi-component strongly interacting massive particle (mSIMP) scenario is reanalyzed using an effective operator approach. It is found that there is an irreducible process in the dark sector that reshuffles the mass densities of SIMP dark matter (DM). This reshuffling mechanism is sensitive to the size of the DM self-interacting cross section.