Seesaw Scale and CP Phases in a Minimal Model of Leptogenesis

TL;DR

This paper explores how the seesaw mechanism links low-energy neutrino measurements to high-scale leptogenesis, showing that CP phases can constrain the seesaw scale in a minimal model.

Contribution

It demonstrates that the seesaw scale relevant for leptogenesis can be constrained by CP phases within a minimal model, connecting low-energy observables to high-energy physics.

Findings

Neutrino mixing angles are expressed in terms of $ heta_{13}$.

Lepton asymmetry depends on CP phases in Dirac and Majorana neutrinos.

Seesaw scale can be constrained by CP phases.

Abstract

The seesaw mechanism to derive the light masses of left-handed neutrinos using heavy masses of right-handed neutrinos gives rise to a connection between low-energy measurables and GUT-scale mechanism. We expresses the neutrino mixing angles in terms of a single variable $\sin\theta_{13}$, whose size was measured recently. The lepton asymmetry from heavy neutrinos via Yukawa coupling is described by CP phases in both Dirac and Majorana type. It is shown that the seesaw scale relevant to the lepton asymmetry can be constrained by CP phase in this minimal model.