Matthew R. Buckley

Scalar Simplified Models for Dark Matter

We introduce a set of minimal simplified models for dark matter interactions with the Standard Model, connecting the two sectors via either a scalar or pseudoscalar particle. These models have a wider regime of validity for dark matter searches at the LHC than the effective field theory approach, while still allowing straightforward comparison to results from non-collider dark matter detection experiments. Such models also motivate dark matter searches in multiple correlated channels. In this paper, we constrain scalar and pseudoscalar simplified models with direct and indirect detection experiments, as well as from existing LHC searches with missing energy plus tops, bottoms, or jets, using the exact loop-induced coupling with gluons. This calculation significantly affects key differential cross sections at the LHC, and must be properly included. We make connections with the Higgs sector, and conclude with a discussion of future searches at the LHC.

Dark matter self-interactions and light force carriers

Recent observations from PAMELA, FERMI, and ATIC point to a new source of high energy cosmic rays. If these signals are due to annihilating dark matter (DM), the annihilation cross section in the present day must be substantially larger than that necessary for thermal freeze-out in the early universe. A new force, mediated by a particle of mass O(100  MeV), leading to a velocity-dependent annihilation cross section—a “Sommerfeld enhancement”—has been proposed as a possible explanation. We point out that such models necessarily increase the DM self-scattering cross section, and use observational bounds on the amount of DM-DM scattering allowed in various astrophysical systems to place constraints on the mass and couplings of the light mediator.

Toward a consistent picture for CRESST, CoGeNT, and DAMA

Three dark matter direct detection experiments (DAMA/LIBRA, CoGeNT, and CRESST-II) have each reported signals which are not consistent with known backgrounds, but resemble that predicted for a dark matter particle with a mass of roughly

Scattering, damping, and acoustic oscillations: Simulating the structure of dark matter halos with relativistic force carriers

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Are There Hints of Light Stops in Recent Higgs Search Results

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Implications of a 130 GeV gamma-ray line for dark matter

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Stops and MET: the shape of things to come

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Asymmetric Dark Matter and Effective Operators

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How Can We Test Seesaw Experimentally

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