Non-relativistic leptogenesis

Understand

In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe.

• We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections.
• We determine the leading order coefficients in these equations, and the first relativistic corrections.
• The non-relativistic approximation works remarkably well.