Revision 1

Superseded · first revision · record

Title: Which mechanism produced the cosmic baryon asymmetry?
Plain: For every billion antiquarks there were about a billion and one quarks in the early universe. Something broke the matter-antimatter balance, and we do not know what.
Precise: Explain $\eta_B = n_B/n_\gamma \sim 6.1e-10$ (CMB and BBN) satisfying the Sakharov conditions, given that SM CP violation and the SM crossover fail by many orders of magnitude. An answer is a mechanism (thermal or resonant leptogenesis, electroweak baryogenesis, Affleck-Dine, or others) with an independent experimental confirmation.
Settled by: Laboratory confirmation of the ingredients of one mechanism, for example lepton number violation plus leptonic CP violation plus heavy neutral leptons for leptogenesis.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: open
Status note: (empty)
Posed since: 1967