Thermal leptogenesis in a 5D split fermion scenario with bulk neutrinos

TL;DR

This paper explores how a five-dimensional split fermion model with bulk neutrinos can produce the universe's matter-antimatter asymmetry through thermal leptogenesis, analyzing parameter constraints numerically.

Contribution

It introduces a hybrid 5D model combining split fermions and bulk neutrinos to study leptogenesis, providing numerical constraints on model parameters.

Findings

Heavy neutrino pairs nearly degenerate in mass are predicted.

CP violation sufficient for baryogenesis can arise from neutrino decays.

Constraints on the size of the extra dimension are derived.

Abstract

We study the thermal leptogenesis in a hybrid model, which combines the so called split fermion model and the bulk neutrino model defined in five dimensional spacetime. This model predicts the existence of a heavy neutrino pair nearly degenerate in mass, whose decays might generate a CP violation large enough for creating the baryon asymmetry of the universe through leptogenesis. We investigate numerically the constraints this sets on the parameters of the model such as the size of the compactified fifth dimension.