Thermal Dark Matter from Freeze-Out of Inverse Decays

Area of Science:

• Cosmology
• Particle Physics
• Astrophysics

Background:

• The nature of dark matter remains one of the most significant unsolved problems in modern physics.
• Thermal relics are a well-motivated class of dark matter candidates, but often face constraints from direct and indirect detection experiments.
• Conventional dark matter searches target strongly interacting or electromagnetically interacting particles, which may not encompass all possibilities.

Purpose of the Study:

• To propose a new class of thermal dark matter candidates.
• To explore a dark matter model where the relic abundance is determined by the freeze-out of inverse decays.
• To identify detection strategies for this novel dark matter candidate.

Main Methods:

• Investigating a thermal dark matter model based on inverse decay freeze-out.
• Analyzing the parametric dependence of the relic abundance on the decay width.
• Exploring the implications of an exponentially small decay width for particle couplings.
• Proposing searches for long-lived particles decaying into dark matter at future experiments.

Main Results:

• A new thermal dark matter candidate is proposed, with abundance determined by inverse decay freeze-out.
• The relic abundance matching observations requires an exponentially small decay width and thus very weak couplings to the Standard Model.
• This dark matter candidate evades conventional detection strategies due to its weak interactions.
• The proposed dark matter can be discovered via searches for long-lived parent particles at future experimental facilities.

Conclusions:

• The proposed inverse decay dark matter offers a compelling, weakly interacting alternative to conventional candidates.
• Future experiments searching for long-lived particles provide a promising avenue for discovering this new dark matter species.
• This work highlights the importance of exploring diverse dark matter models beyond standard detection paradigms.