Two component dark matter

TL;DR

This paper proposes a two-component dark matter model to explain cosmic ray excesses, with one stable and one metastable particle, fitting observational data without requiring density spikes and discussing potential collider signals.

Contribution

It introduces a simple two-component dark matter model with a metastable particle to account for cosmic ray excesses, avoiding the need for density spikes.

Findings

Successfully explains PAMELA positron excess and e+ + e- data

Allows large boost factors without local density spikes

Provides parameter constraints and collider signal predictions

Abstract

We explain the PAMELA positron excess and the PPB-BETS/ATIC e+ + e- data using a simple two component dark matter model (2DM). The two particle species in the dark matter sector are assumed to be in thermal equilibrium in the early universe. While one particle is stable and is the present day dark matter, the second one is metastable and decays after the universe is 10^-8 s old. In this model it is simple to accommodate the large boost factors required to explain the PAMELA positron excess without the need for large spikes in the local dark matter density. We provide the constraints on the parameters of the model and comment on possible signals at future colliders.