Thermal Relic Targets with Exponentially Small Couplings

Area of Science:

• Cosmology
• Particle Physics
• Astrophysics

Background:

• The production mechanism of dark matter in the early Universe dictates constraints on its fundamental properties, such as its interaction strength.
• Annihilation into Standard Model particles is a common theoretical production pathway for dark matter, leading to specific experimental targets for its coupling strength.

Purpose of the Study:

• To explore alternative dark matter production mechanisms beyond simple annihilation.
• To investigate the implications of inelastic scattering for dark matter coupling strengths and experimental search strategies.
• To identify new thermal relic targets for direct detection and fixed-target experiments.

Main Methods:

• Theoretical modeling of dark matter production via inelastic scattering in the early Universe thermal bath.
• Comparison of coupling strength requirements for inelastic scattering versus annihilation production.
• Application of the inelastic scattering model to dark matter production via interactions with electrons.

Main Results:

• Dark matter production through inelastic scattering requires exponentially smaller couplings compared to annihilation.
• Inelastic scattering provides a viable mechanism for producing dark matter with very weak interactions.
• Dark matter produced via inelastic scattering off electrons presents novel thermal relic targets for experimental searches.

Conclusions:

• Inelastic scattering is a crucial alternative mechanism for dark matter production, relaxing constraints on its coupling strength.
• The study highlights the importance of considering diverse production channels to fully explore the dark matter parameter space.
• Dark matter produced via inelastic scattering with electrons offers promising new avenues for direct detection and fixed-target experiments.