Z-Portal Continuum Dark Matter

Area of Science:

• Cosmology and particle physics
• Theoretical physics
• Dark matter research

Background:

• The nature of dark matter (DM) remains one of the most significant unsolved problems in physics.
• The standard WIMP (weakly interacting massive particle) paradigm faces challenges, motivating alternative DM candidates.
• Understanding DM's composition is crucial for comprehending the Universe's structure and evolution.

Purpose of the Study:

• To investigate the theoretical possibility of dark matter as a gapped continuum.
• To introduce and analyze the weakly interacting continuum (WIC) model as a realization of continuum dark matter.
• To assess the WIC model's consistency with observational and experimental constraints.

Main Methods:

• Development of the weakly interacting continuum (WIC) model, coupled to the Standard Model via a Z portal.
• Calculation of thermal dark matter relic density within the WIC framework.
• Analysis of direct detection cross-sections, considering continuum kinematics.
• Investigation of constraints from cosmic microwave background (CMB) observations on potential late-time decays of continuum DM states.
• Exploration of collider signatures for WIC production.

Main Results:

• The WIC model naturally predicts a thermal relic density consistent with cosmological observations, mirroring the "WIMP miracle."
• Direct detection cross-sections are significantly suppressed compared to traditional Z-portal WIMP models due to continuum kinematics.
• Cosmic microwave background observations constrain the decay properties of continuum DM states.
• Collider production of WICs can lead to distinctive cascade-decay signatures.
• The proposed Z-portal WIC model is shown to be a fully viable dark matter candidate.

Conclusions:

• A gapped continuum is a plausible alternative to particle-based dark matter.
• The Z-portal WIC model provides a compelling theoretical framework for continuum dark matter.
• The WIC model aligns with current cosmological and experimental data, offering testable predictions for future investigations.