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Cancellation Mechanism for Dark-Matter-Nucleon Interaction.

Christian Gross1, Oleg Lebedev1, Takashi Toma2

  • 1Department of Physics and Helsinki Institute of Physics, Gustaf Hällströmin katu 2, FI-00014 Helsinki, Finland.

Physical Review Letters
|December 9, 2017
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Summary

A new Higgs portal dark-matter model features a complex scalar. Its direct detection cross-section naturally vanishes due to a softly broken symmetry, satisfying all constraints.

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Area of Science:

  • Particle Physics
  • Cosmology
  • Astrophysics

Background:

  • The Standard Model of particle physics requires extensions to account for dark matter.
  • Higgs portal models are a popular framework for introducing dark matter candidates.
  • Direct detection experiments aim to observe dark matter interactions with ordinary matter.

Purpose of the Study:

  • To investigate a simple Higgs portal dark-matter model.
  • To analyze the direct dark matter detection cross-section within this model.
  • To determine if electroweak-scale dark matter can naturally satisfy phenomenological constraints.

Main Methods:

  • Considered a Standard Model extension with a complex scalar field.
  • Analyzed the imaginary component of the scalar as a dark matter candidate.
  • Calculated the tree-level direct detection cross-section at zero momentum transfer.
  • Investigated the role of a softly broken symmetry in the model.

Main Results:

  • The direct dark matter detection cross-section vanishes at tree level and zero momentum transfer.
  • This vanishing is due to a cancellation arising from a softly broken symmetry.
  • The cancellation mechanism is independent of mediator masses.
  • Electroweak-scale dark matter in this model naturally meets all phenomenological constraints.

Conclusions:

  • The proposed Higgs portal model provides a compelling candidate for dark matter.
  • The vanishing direct detection cross-section offers a unique signature for this model.
  • This framework naturally accommodates dark matter within the electroweak scale, consistent with observations.