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Her Dark Materials: Comparison of Semiconducting Targets for Multi-Channel Direct Detection of Light Dark Matter

ORAL

Abstract

The nature of dark matter (DM) remains one of the greatest mysteries of physics. Experiments searching for DM on the mass scale of WIMPs have not established a DM signal, whilst the lighter mass range of keV to GeV is well-motivated yet unexplored. Expanding the reach of direct detection experiments down to light DM masses requires new ideas for the types of excitation that are possible and efficient pathways for their detection. Correspondingly, materials with a strong response must be identified for use as targets.

We have designed a methodology for evaluating the sensitivity of semiconducting materials to DM excitations based on density functional theory calculations.1 The model takes into account three complementary interactions: nuclear recoils, electron transitions across band gaps and single phonon excitations. We include a novel multi-channel response.

Using this framework, we have calculated the performance of 25 materials for a comparison of target sensitivities.2 We identify the materials parameters that must be optimized in order to maximize experimental reach. Furthermore, we evaluate a two-dimensional material which can exhibit the “smoking gun” DM signature of daily and annual modulation.

1arXiv:1910.08092
2arXiv:1910.10716

Presenters

  • Katherine Inzani

    Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, USA

Authors

  • Katherine Inzani

    Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, USA

  • Tanner Trickle

    Department of Physics, University of California, Berkeley

  • Zhengkang Zhang

    Department of Physics, University of California, Berkeley

  • Kathryn Zurek

    Walter Burke Institute for Theoretical Physics, California Institute of Technology

  • Sinéad Griffin

    Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, USA