What question did this study set out to answer?

This research aims to compute the CP-asymmetry factor from Majorana fermion decays in U(1) extensions of the Standard Model.

April 24, 2026Open Access

Leptogenesis in U(1) Extensions of the Standard Model

Key Points

This research aims to compute the CP-asymmetry factor from Majorana fermion decays in U(1) extensions of the Standard Model.
Utilized a semi-classical approach for estimating baryogenesis via leptogenesis.
Computed the finite temperature CP-asymmetry factor at next-to-leading order in perturbation theory.
Analyzed one-loop corrections and their impact on predictions.
Provided benchmark predictions for the CP-asymmetry factor depending on temperature in the superweak extension.
Highlighted the role of one-loop corrections in achieving meaningful physical expressions.

Abstract

We present the ingredients of a computation needed for a semi-classical treatment for estimating the amount of baryogenesis via leptogenesis. Our main focus is on the computation of the finite temperature CP-asymmetry factor originating from Majorana fermion decays into a lepton and a scalar particle at next-to-leading order in perturbation theory. Such decays emerge naturally in U(1) extensions of the Standard Model, such as the superweak extension (SWSM). We emphasize the importance of all cuts in the one-loop corrections in order to obtain physically meaningful expressions and present benchmark predictions for the CP-asymmetry factor as a function of temperature in the SWSM. Abstract Published by the Jagiellonian University 2026 authors

Leptogenesis in U(1) Extensions of the Standard Model

Key Points

Abstract

Cite This Study