Particle Astrophysics Seminar: Leak-In Dark Matter

  • Jan. 13, 2020, 2:00 pm US/Central
  • Curia II
  • Cristian Gaidau, University of Illinois

I will discuss leak-in dark matter, a novel out-of-equilibrium origin for the dark matter (DM) in the universe. Leak-in DM is a minimal, internally-thermalized, hidden sector populated from an out-of-equilibrium, feeble connection to the hotter standard model (SM) sector. When this connection is renormalizable, the colder sector undergoes an extended phase of non-adiabatic evolution largely independent of initial conditions, which we dub “leak-in.” I will discuss the leak-in phase overall and establish the general properties of dark matter that freezes out from a radiation bath undergoing such a leak-in phase. More concretely, I consider a model where the SM has an out-of-equilibrium B-L vector portal interaction with a minimal hidden sector. I will discuss the interplay between leak-in and freeze in processes in this theory and demonstrate regions where leak-in yields the full relic abundance. I will then discuss a variety of experiments which serve as sensitive probes of leak-in dark matter.