Physicists tie matter-antimatter imbalance to heaviest right-handed neutrino

Rishav Roshan (Southampton) and Sudipta Show (IIT Kanpur) propose in Physical Review Letters that the heaviest right-handed neutrino in minimal seesaw models shifted charged-lepton equilibration in the early universe. Its slow radiation-to-matter transition changes the expansion rate and the timing of leptogenesis. Neutrino-oscillation and primordial gravitational-wave data could indirectly constrain the scenario.

• Paper published in Physical Review Letters, Vol. 137, Issue 11
• Heaviest right-handed neutrino stays out of equilibrium for long periods
• Shifted equilibration temperature alters the timing of leptogenesis
• Neutrino oscillations and primordial gravitational waves could test it