# Leptogenesis in the Neutrino Option

## TL;DR

This paper demonstrates that the Neutrino Option, which generates the electroweak scale via PeV-scale seesaw neutrinos, can be compatible with resonant leptogenesis, producing the universe's baryon asymmetry through low-energy CP violation phases.

## Contribution

It shows the compatibility of the Neutrino Option with resonant leptogenesis in a minimal seesaw model with two heavy neutrinos, identifying viable parameter space and CP violation sources.

## Key findings

- Successful leptogenesis occurs for neutrino masses between 1.2 and 8.8 million GeV.
- Leptogenesis requires a tiny mass splitting of about 10^{-8} between heavy neutrinos.
- Baryon asymmetry can be generated solely from low-energy CP violation phases.

## Abstract

We examine the compatibility between the Neutrino Option, in which the electroweak scale is generated by PeV mass type I seesaw Majorana neutrinos, and leptogenesis. We find the Neutrino Option is consistent with resonant leptogenesis. Working within the minimal seesaw scenario with two heavy Majorana neutrinos $N_{1,2}$, which form a pseudo-Dirac pair, we explore the viable parameter space. We find that the Neutrino Option and successful leptogenesis are compatible in the cases of a neutrino mass spectrum with normal (inverted) ordering for $1.2 \times 10^6 < M \text{ (GeV)} < 8.8 \times 10^6$ ($2.4 \times 10^6 < M \text{ (GeV)} < 7.4 \times 10^6$), with $M = (M_1 + M_2)/2$ and $M_{1,2}$ the masses of $N_{1,2}$. Successful leptogenesis requires that $\Delta M/M \equiv (M_2 - M_1)/M \sim 10^{-8}$. We further show that leptogenesis can produce the baryon asymmetry of the Universe within the Neutrino Option scenario when the requisite CP violation in leptogenesis is provided exclusively by the Dirac or Majorana low energy CP violation phases of the PMNS matrix.