Decaying Dark Matter Baryons in a Composite Messenger Model

TL;DR

This paper proposes a model where a heavy baryonic bound state from messenger quarks acts as dark matter, which is metastable and can explain the positron excess observed by PAMELA.

Contribution

It introduces a novel composite messenger model where baryonic bound states serve as dark matter candidates with natural metastability.

Findings

Baryonic dark matter can have a mass around 100 TeV.

Decay of this dark matter explains PAMELA positron excess.

The model naturally accounts for dark matter stability and decay.

Abstract

A baryonic bound state with a mass of O(100) TeV, which is composed of strongly interacting messenger quarks in the low scale gauge mediation, can naturally be the cold dark matter. Interestingly, we find that such a baryonic dark matter is generically metastable, and the decay of this dark matter can naturally explain the anomalous positron flux recently observed by the PAMELA collaboration.