Leptogenesis: Improving predictions for experimental searches

TL;DR

This paper reviews recent theoretical advances in leptogenesis, emphasizing improved calculations for low-scale scenarios where heavy neutrinos could be detected experimentally, and discusses implications for baryon asymmetry and neutrinoless double beta decay.

Contribution

It provides updated theoretical descriptions and calculations for low-scale leptogenesis, enhancing the connection between neutrino physics and experimental searches.

Findings

Enhanced accuracy in leptogenesis predictions at TeV scale

Potential detectability of heavy neutrinos in current and future experiments

Significant thermal corrections in early universe transport equations

Abstract

Heavy right handed neutrinos could not only explain the observed neutrino masses via the seesaw mechanism, but also generate the baryon asymmetry of the universe via leptogenesis due to their CP-violating interactions in the early universe. We review recent progress in the theoretical description of this nonequilibrium process. Improved calculations are particularly important for a comparison with experimental data in testable scenarios with Majorana masses below the TeV scale, in which the heavy neutrinos can be found at the LHC, in the NA62 experiment, at T2K or in future experiments, including SHiP, DUNE and experiments at the FCC, ILC or CEPC. In addition, the relevant source of CP-violation may be experimentally accessible, and the heavy neutrinos can give a sizable contribution to neutrinoless double $\beta$ decay. In these low scale leptogenesis scenarios, the matter-antimatter asymmetry is generated at temperatures when the heavy neutrinos are relativistic, and thermal corrections to the transport equations in the early universe are large.