Predicting the baryon asymmetry with degenerate right-handed neutrinos

• Published in: The journal of high energy physics Vol. 2023; no. 11; pp. 153 - 37
• Main Authors: Sandner, S., Hernández, P., López-Pavón, J., Rius, N.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 22.11.2023; Springer Nature B.V; SpringerOpen
• Subjects: Antimatter; Approximation; Asymmetry; Baryo-and Leptogenesis; Baryons; Classical and Quantum Gravitation; CP violation; Early Universe Particle Physics; Eigenvalues; Electroweak model; Elementary Particles; Fermions; Flavor (particle physics); High energy physics; Leptons; Light; Neutrinos; Phase transitions; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Standard model (particle physics); Sterile or Heavy Neutrinos; String Theory; Symmetry; Sterile or Heavy Neutrinos; Baryo-and Leptogenesis; Early Universe Particle Physics
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP11(2023)153

A bstract We consider the generation of a baryon asymmetry in an extension of the Standard Model with two singlet Majorana fermions that are degenerate above the electroweak phase transition. The model can explain neutrino masses as well as the observed matter-antimatter asymmetry, for masses of the heavy singlets below the electroweak scale. The only physical CP violating phases in the model are those in the PMNS mixing matrix, i.e. the Dirac phase and a Majorana phase that enter light neutrino observables. We present an accurate analytic approximation for the baryon asymmetry in terms of CP flavour invariants, and derive the correlations with neutrino observables. We demonstrate that the measurement of CP violation in neutrino oscillations as well as the mixings of the heavy neutral leptons with the electron, muon and tau flavours suffice to pin down the matter-antimatter asymmetry from laboratory measurements.