Positrons and antiprotons from inert doublet model dark matter

TL;DR

This paper investigates antimatter production from inert doublet model dark matter annihilation, analyzing different mass candidates and their ability to explain cosmic ray data, highlighting potential signals and limitations.

Contribution

It introduces a detailed analysis of antimatter signals from inert doublet dark matter, considering various masses and comparing predictions with recent cosmic ray observations.

Findings

Light dark matter candidate produces potentially observable antimatter fluxes.

Intermediate mass candidate cannot explain observed cosmic ray excesses.

Heavy candidate can fit PAMELA data with large enhancement factors.

Abstract

In the framework of the Inert Doublet Model, a very simple extension of the Standard Model, we study the production and propagation of antimatter in cosmic rays coming from annihilation of a scalar dark matter particle. We consider three benchmark candidates, all consistent with the WMAP cosmic abundance and existing direct detection experiments, and confront the predictions of the model with the recent PAMELA, ATIC and HESS data. For a light candidate, M_{DM} = 10 GeV, we argue that the positron and anti-proton fluxes may be large, but still consistent with expected backgrounds, unless there is an enhancement (boost factor) in the local density of dark matter. There is also a substantial anti-deuteron flux which might be observable by future experiments. For a candidate with M_{DM} = 70 GeV, the contribution to positron and anti-proton fluxes is much smaller than the expected backgrounds. Even if a boost factor is invoked to enhance the signals, the candidate is unable to explain the observed positron and anti-proton excesses. Finally, for a heavy candidate, M_{DM} = 10 TeV, it is possible to fit the PAMELA excess (but, unfortunately, not the ATIC one) provided there is a large enhancement, either in the local density of dark matter or through the Sommerfeld effect.