http://arxiv.org/abs/1707.07940
The Madala hypothesis was proposed by members of the Wits-ATLAS group to account for several anomalies in both ATLAS and CMS data at the LHC. This hypothesis extends the standard model through the addition of two scalar bosons and a hidden sector that can provide a dark matter candidate. This hidden sector interacts with the standard model only through the mediation of one of these scalars S. The couplings of S are not amenable to investigation in current collider data and so are assumed to be Higgs-like to reduce the parameter space of the model. Our previous work (Beck & Colafrancesco 2016) has shown that these couplings can be limited via indirect dark matter detection experiments in gamma-rays (for resonant annihilations into S). Here we will treat the dark matter and S masses independently, and we generalise our previous work and examine what fraction of the cosmological dark matter abundance can be accounted for by particles in the hidden sector of the Madala hypothesis dark matter when these annihilate to standard model products via a Higgs-like S. We will also extend our gamma-ray analysis of Madala hypothesis dark matter to include the constraints of diffuse radio data from the Coma galaxy cluster in addition to the Fermi-LAT gamma-ray data from both this target and the Reticulum II dwarf galaxy.
Our analysis indicates that either the Madala hypothesis cannot provide the bulk of cosmological dark matter, or the S boson cannot be simply Higgs-like. These apply unless the candidate particle exceeds a mass of 200 GeV. Both these scenarios may reduce the attractiveness of the hypothesis as the second case will imply that many free parameters must be added to describe S, greatly weakening fits for the model. To investigate the full consequences of this further work will necessitate using larger astrophysical data sets to strongly constrain details about S.
G. Beck and S. Colafrancesco
Wed, 26 Jul 17
32/68
Comments: 6 Pages, 2 figures, submitted to the proceedings of the South African Institute of Physics Conference 2017