Why dark matter and atoms weigh nearly the same—and what flavor symmetry has to do with it

The authors propose that a gauged flavor symmetry—the same force that shapes why electron and top quark masses differ wildly—also generates dark matter through leptogenesis. Right-handed neutrinos decay to create a lepton asymmetry, which is then split between ordinary matter and dark matter by quantum processes, naturally explaining why visible and dark matter have comparable mass scales. Meson oscillations and rare B decays already constrain this scenario tightly, with mirror fermions potentially appearing at future colliders.