Global analysis of the pMSSM in light of the Fermi GeV excess: prospects for the LHC Run-II and astroparticle experiments

Abstract

We present a new global fit of the 19-dimensional phenomenological Minimal\nSupersymmetric Standard Model (pMSSM-19) that comply with all the latest\nexperimental results from dark matter indirect, direct and accelerator dark\nmatter searches. We show that the model provides a satisfactory explanation of\nthe excess of gamma-rays from the Galactic centre observed by the Fermi~Large\nArea Telescope, assuming that it is produced by the annihilation of neutralinos\nin the Milky Way halo. We identify two regions that pass all the constraints:\nthe first corresponds to neutralinos with a mass ~80-100 GeV annihilating into\nWW with a branching ratio of 95% ; the second to heavier neutralinos, with mass\n~180-200 GeV annihilating into t tbar with a branching ratio of 87%. We show\nthat neutralinos compatible with the Galactic centre GeV excess will soon be\nwithin the reach of LHC run-II -- notably through searches for charginos and\nneutralinos, squarks and light smuons -- and of Xenon1T, thanks to its\nunprecedented sensitivity to spin-dependent cross-section off neutrons.\n