Freeze-out of baryon number in low-scale leptogenesis

Understand

Low-scale leptogenesis provides an economic and testable description of the origin of the baryon asymmetry of the Universe.

• In this scenario, the baryon asymmetry of the Universe is reprocessed from the lepton asymmetry by electroweak sphaleron processes.
• Provided that sphalerons are fast enough to maintain equilibrium, the values of the baryon and lepton asymmetries are related to each other.
• Usually, this relation is used to find the value of the baryon asymmetry at the time of the sphaleron freeze-out.