Baryon and Dark Matter Genesis from Strongly Coupled Strings
  D3-brane probes of E-type Yukawa points lead to strongly coupled nearly conformal sectors nearby the Standard Model (visible sector) which are motivated by F-theory GUTs. Realistic visible sector brane configurations induce a seesaw mass hierarchy in the hidden sector with light GUT singlets charged under a strongly coupled hidden sector U(1). Interpreting these GUT singlets as dark matter, this leads to a matter genesis scenario where the freeze out and subsequent decay of heavy mediators between the two sectors simultaneously populates comparable amounts of baryon and dark matter asymmetry. Generating a net matter asymmetry requires a generational structure in the probe sector which is absent at weak string coupling, but is automatically realized at strong string coupling via towers of dyonic bound states corresponding to multi-prong string junctions. The hidden U(1) couples to the visible sector through both electric and magnetic kinetic mixing terms, providing an efficient means to deplete the symmetric component of dark matter. The mass of the dark matter is of order ~ 10 GeV. The dark matter mass and the matter asymmetry are both controlled by the scale of conformal symmetry breaking ~ 10^(9) - 10^(13) GeV, with the precise relation between the two set by details of the visible sector brane configuration. 
Jonathan J. Heckman and Soo-Jong Rey
hep-th astro-ph.CO hep-ph