# Initial condition for baryogenesis via neutrino oscillation

## TL;DR

This paper investigates how initial conditions, especially from higher-dimensional operators, affect baryogenesis via neutrino oscillations, revealing that initial abundance can significantly expand viable parameter space.

## Contribution

It introduces the impact of higher-dimensional operators on initial right-handed neutrino abundance, altering baryogenesis predictions and expanding the viable parameter space.

## Key findings

- Initial abundance from higher-dimensional operators can modify baryogenesis outcomes.
- The parameter space for successful baryogenesis is enlarged when initial conditions are considered.
- The effect is significant when the strong washout of asymmetry is absent.

## Abstract

We consider a baryogenesis scenario via the oscillation of right-handed neutrinos with Majorana masses of the order of GeV, which are also responsible for neutrino masses by the seesaw mechanism. We study how the initial condition alters the prediction of the present baryon asymmetry by this mechanism. It is usually assumed that the abundance of right-handed neutrinos is zero after the reheating of the inflationary universe and they are produced in scattering processes by the renomalizable Yukawa interaction. However, the higher-dimensional operator with right-handed neutrinos may provide an additional production which is most effective at the reheating epoch. It is shown that such an initial abundance of right-handed neutrinos can significantly modify the prediction when the strong washout of the asymmetry is absent. This leads to the parameter space of the model for the successful baryogenesis being enlarged.