Probing the Dark Sector with Dark Matter Bound States

Area of Science:

• Particle Physics
• Cosmology
• Astrophysics

Background:

• A proposed dark sector model involves dark matter particles (χ) interacting with a lighter dark force mediator (V).
• This model is motivated by discrepancies observed in galactic halo shapes between simulations and astronomical data.
• Such models present challenges for traditional direct detection and collider search strategies.

Purpose of the Study:

• To investigate the potential of B factory experiments to constrain dark matter models with light mediators.
• To explore the production and decay of dark matter bound states (ηD and ϒD) as a viable search channel.
• To establish new constraints on the parameter space of dark matter models using existing experimental data.

Main Methods:

• Analyzing the production of ηD and ϒD bound states via e+e- collisions at B factories.
• Simulating the decay of these bound states into multiple dark force mediators (V), which then decay into charged leptons and pions (l+l-).
• Utilizing existing search results from BABAR and Belle experiments to set limits.

Main Results:

• e+e- → ηD + V or ϒD + γ production at B factories is significant for αD > 0.1.
• The decay channels ηD → 2V → 2(l+l-) and ϒD → 3V → 3(l+l-) produce multiple charged leptons and pions.
• The absence of these specific final states in current BABAR and Belle searches imposes new constraints on the model's parameter space.

Conclusions:

• B factory experiments provide a powerful tool to probe dark matter models with light mediators through bound state searches.
• Existing experimental data already constrain significant portions of the parameter space for these dark matter models.
• Future searches for multiple dark force mediator bremsstrahlung (e+e- → χχ̄ + nV) will enhance sensitivity to self-interacting dark matter.