A description of the Galactic Center excess in the Minimal Supersymmetric Standard Model

Abstract

Observations with the Fermi Large Area Telescope (LAT) indicate an excess in gamma rays originating from the center of our Galaxy. A possible explanation for this excess is the annihilation of Dark Matter particles. We have investigated the annihilation of neutralinos as Dark Matter candidates within the phenomenological Minimal Supersymmetric Standard Model (pMSSM). An iterative particle filter approach was used to search for solutions within the pMSSM. We found solutions that are consistent with astroparticle physics and collider experiments, and provide a fit to the energy spectrum of the excess. The neutralino is a Bino/Higgsino or Bino/Wino/Higgsino mixture with a mass in the range 84 − 92 GeV or 87 − 97 GeV annihilating into W bosons. A third solutions is found for a neutralino of mass 174 − 187 GeV annihilating into top quarks. The best solutions yield a Dark Matter relic density 0.06 < Ωh 2 < 0.13. These pMSSM solutions make clear forecasts for LHC, direct and indirect DM detection experiments. If the pMSSM explanation of the excess seen by Fermi-LAT is correct, a DM signal might be discovered soon.

Harmonizing the MSSM with the Galactic Center excess

“…Note that this is the leading uncertainty for E γ 40 GeV. Furthermore, we include a 10% uncertainty from the fragmentation function for photons [18], treated as un-correlated between energy bins and Gaussian distributed. Finally, we include the systematic error on the Fermi-LAT effective area [21], treated as fully correlated between bins and also Gaussian distributed.…”

“…We examine how this wide range of spectra opens up regions of the MSSM parameter space describing the excess [14] by performing global fits to these spectra in the SFitter framework [15], consistently with the thermal relic density, the light Higgs boson mass, and the standard set of low energy indirect constraints. The power of such a global analysis rests in its ability to interpret the wide range of relevant experimental observations [16][17][18][19]. .…”

A robust excess in the cosmic-ray antiproton spectrum: Implications for annihilating dark matter

“…Moreover, an excess of GeV-scale gamma-rays from the Inner Galaxy has now been firmly confirmed [13][14][15][16][17][18][19]. Although these two signals are sensitive to very different systematic uncertainties and backgrounds, it is intriguing that they could both be explained by a ∼60 GeV dark matter particle with an annihilation cross section near that predicted for a generic thermal relic [17,[20][21][22][23]. The concordance between these two signals is suggestive and provides considerable motivation for additional indirect searches for dark matter (see e.g.…”

Dark matter in leptophilic Higgs models after the LHC run I

“…As expected the cross section decreases as the mass of the pseudoscalar increases, however we can see that there is still a large range of parameters which fit the Galactic Center excess, even when the pseudoscalar and dark matter masses are far from being in resonance. It is notable that a leptophilic Higgs model furnishes a viable mediator between the visible sector and the dark matter which provides a sufficiently large annihilation cross section; in Type-II Higgs models, a Higgs mediator which can explain the Galactic Center anomaly without a resonance enhancement tends to require additional light states which are well-constrained from direct detection and collider searches [106][107][108][109][110][111][112]. As the mediators considered here are leptophilic, such constraints are easily avoided.…”