Dark Solar Wind.

Area of Science:

• * Particle Physics
• * Astrophysics
• * Cosmology

Background:

• * The nature of dark matter remains one of the most significant unsolved problems in physics.
• * Exploring dark sector models beyond the simplest non-interacting scenarios is crucial for understanding dark matter.
• * Solar emissions can potentially carry signatures of exotic particles from the dark sector.

Purpose of the Study:

• * To investigate the behavior of strongly self-interacting dark sector particles emitted from the sun.
• * To model the resulting outflow and its properties, such as number density and particle energy.
• * To explore a specific dark sector model involving millicharged particles and a dark photon.

Main Methods:

• * Theoretical modeling of a dark sector with strong self-interactions leading to thermalization.
• * Analysis of the fluid-like behavior and acceleration of the particle outflow.
• * Calculation of number density and average energy per particle for the outflow.

Main Results:

• * The outflow of self-interacting dark sector particles behaves as a fluid, accelerating to relativistic velocities.
• * The local outflow exhibits a number density at least 10^3 higher and an average energy per particle 10^3 lower than non-interacting scenarios.
• * A model with millicharged particles interacting via a dark photon successfully reproduces these phenomena.

Conclusions:

• * Strong self-interactions in the dark sector can lead to unique, observable phenomena like a dense plasma wind.
• * The predicted signatures of this millicharged plasma wind encourage new experimental directions for dark sector searches.
• * This study highlights how deviations from simple dark matter models can yield drastically different, yet testable, outcomes.