High Energy Positrons and Gamma Radiation from Decaying Constituents of a two-component Dark Atom Model

Preprint number: CP3-Origins-2015-33 DNRF90 and DIAS-2015-33
Authors: Kostya Belotsky (National Research Nuclear University, Moscow), Maxim Khlopov (APC Laboratory 10, Paris), Christoforos Kouvaris (CP3-Origins & DIAS), and Maxim Laletin (National Research Nuclear University, Moscow)
External link: arXiv.org

We study a two component dark matter candidate inspired by the Minimal Walking Technicolor model. Dark matter consists of a dominant SIMP-like dark atom component made of bound states between primordial helium nuclei and a doubly charged technilepton, and a small WIMP-like component made of another dark atom bound state between a doubly charged technibaryon and a technilepton. This scenario is consistent with direct search experimental findings because the dominant SIMP component interacts too strongly to reach the depths of current detectors with sufficient energy to recoil and the WIMP-like component is too small to cause significant amount of events. In this context a metastable technibaryon that decays to $e^+e^+$, $\mu^+ \mu^+$ and $\tau^+ \tau^+$ can in principle explain the observed positron excess by AMS-02 and PAMELA, while being consistent with the photon flux observed by FERMI/LAT. We scan the parameters of the model and we find the best possible fit to the latest experimental data. We find that there is a small range of parameter space that this scenario can be realised under certain conditions regarding the cosmic ray propagation and the final state radiation. This range of parameters fall inside the region where the current run of LHC can probe, and therefore it will soon be possible to either verify or exclude conclusively this model of dark matter.