Leptogenesis without on-shell right-handed neutrinos

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Cléry, Simon, Ibarra, Alejandro, Yonar, Onur
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914594178465792
author Cléry, Simon
Ibarra, Alejandro
Yonar, Onur
author_facet Cléry, Simon
Ibarra, Alejandro
Yonar, Onur
contents We propose a novel mechanism for generating the baryon asymmetry of the Universe through leptogenesis in a scenario where the right-handed neutrinos are heavier than the maximal temperature of the Universe, and are never produced on-shell neither by thermal nor by non-thermal mechanisms. We introduce a new scalar field, $ϕ$, lighter than the right-handed neutrinos, that couples to the latter via a Yukawa coupling, so that it decays into two lepton doublets and two higgs doublets via off-shell right-handed neutrinos. Then, we derive the CP asymmetry arising from the interference between tree-level and loop diagrams in the four-body decay, and we show that the generated baryon asymmetry can reproduce the observed value both in a scenario where $ϕ$ is responsible for the reheating of the Universe, and in a scenario where $ϕ$ is a generic scalar that remains in thermal equilibrium with the plasma.
format Preprint
id arxiv_https___arxiv_org_abs_2605_24163
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Leptogenesis without on-shell right-handed neutrinos
Cléry, Simon
Ibarra, Alejandro
Yonar, Onur
High Energy Physics - Phenomenology
Cosmology and Nongalactic Astrophysics
We propose a novel mechanism for generating the baryon asymmetry of the Universe through leptogenesis in a scenario where the right-handed neutrinos are heavier than the maximal temperature of the Universe, and are never produced on-shell neither by thermal nor by non-thermal mechanisms. We introduce a new scalar field, $ϕ$, lighter than the right-handed neutrinos, that couples to the latter via a Yukawa coupling, so that it decays into two lepton doublets and two higgs doublets via off-shell right-handed neutrinos. Then, we derive the CP asymmetry arising from the interference between tree-level and loop diagrams in the four-body decay, and we show that the generated baryon asymmetry can reproduce the observed value both in a scenario where $ϕ$ is responsible for the reheating of the Universe, and in a scenario where $ϕ$ is a generic scalar that remains in thermal equilibrium with the plasma.
title Leptogenesis without on-shell right-handed neutrinos
topic High Energy Physics - Phenomenology
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2605.24163