On the evolution process of two-component dark matter in the Sun

TL;DR

This paper models the evolution of two-component dark matter in the Sun, highlighting how heterogeneous self-scattering influences capture and annihilation rates, which is vital for indirect detection strategies.

Contribution

It introduces a formalism for two-component dark matter evolution in the Sun, emphasizing the role of heterogeneous self-scattering in mutual capture enhancement.

Findings

Heterogeneous self-scattering significantly increases DM capture in the Sun.

The evolution processes of two DM species are interconnected through this scattering.

Implications for DM indirect detection are especially notable when the two masses are similar.

Abstract

We introduce dark matter (DM) evolution process in the Sun under a two-component DM (2DM) scenario. Both DM species $\chi$ and $\xi$ with masses heavier than 1 GeV are considered. In this picture, both species could be captured by the Sun through DM-nucleus scattering and DM self-scatterings, e.g. $\chi\chi$ and $\xi\xi$ collisions. In addition, the heterogeneous self-scattering due to $\chi$ and $\xi$ collision is essentially possible in any 2DM models. This new introduced scattering naturally weaves the evolution processes of the two DM species that was assumed to evolve independently. Moreover, the heterogeneous self-scattering enhances the number of DM being captured in the Sun mutually. This effect significantly exists in a broad range of DM mass spectrum. We have studied this phenomena and its implication for the solar-captured DM annihilation rate. It would be crucial to the DM indirect detection when the two masses are close. General formalism of the 2DM evolution in the Sun as well as its kinematics are studied.