Unitarity and CP violation in leptogenesis at NLO: general considerations and top Yukawa contributions

Understand

With an emphasis on unitarity and CPT requirements, we study the inclusion of CP-violating processes in baryogenesis at next-to-leading order, particularly those involving the top Yukawa interaction in leptogenesis.

• We show that there are more contributions than previously considered, but also important cancellations.
• Some of these involve the interference of connected with disconnected diagrams.
• We also discuss on the application of the Kinoshita-Lee-Nauenberg theorem to treat the infrared divergences that are common at next-to-leading order.