Slightly Non-Minimal Dark Matter in PAMELA and ATIC

TL;DR

This paper proposes a simple dark matter model involving a light scalar that explains positron excesses observed by PAMELA and ATIC without increasing anti-proton levels, and predicts very low nucleon coupling.

Contribution

It introduces a novel dark matter model with a light scalar mediator that naturally accounts for specific cosmic ray observations and remains consistent with direct detection constraints.

Findings

Explains positron excess without anti-proton surplus

Predicts very small nucleon coupling below detection limits

Analyzes effects in early universe and galaxy environments

Abstract

We present a simple model in which dark matter couples to the standard model through a light scalar intermediary that is itself unstable. We find this model has several notable features, and allows a natural explanation for a surplus of positrons, but no surplus of anti-protons, as has been suggested by early data from PAMELA and ATIC. Moreover, this model yields a very small nucleon coupling, well below the direct detection limits. In this paper we explore the effect of this model in both the early universe and in the galaxy.