Dark Solar Wind

We study the solar emission of light dark sector particles that self-interact strongly enough to self-thermalize. The resulting outflow behaves like a fluid which accelerates under its own thermal pressure to highly relativistic bulk velocities in the solar system. Compared to the ordinary noninteracting scenario, the local outflow has at least-103 higher number density and correspondingly at least-103 lower average energy per particle. We show how this generic phenomenon arises in a dark sector composed of millicharged particles strongly self-interacting via a dark photon. The millicharged plasma wind emerging in this model has novel yet predictive signatures that encourages new experimental directions. This phenomenon demonstrates how a small step away from the simplest models can lead to radically different outcomes and thus motivates a broader search for dark sector particles.

Automated summary

We studied the emission of self-thermalizing light dark sector particles in the solar system. We found that this phenomenon is commonly observed in a dark sector composed of millicharged particles interacting via a dark photon, resulting in a plasma wind with distinctive and predictable signatures.