Leptogenesis in an anomaly-free $\mathrm{U}(1)$ extension with higher-dimensional operators

TL;DR

This paper proposes an anomaly-free U(1) extended model that explains baryon asymmetry via TeV-scale resonant leptogenesis, incorporating higher-dimensional operators, and predicts collider-testable signatures like same-sign dileptons.

Contribution

It introduces a novel anomaly-free U(1) extension with higher-dimensional operators that generate neutrino masses and enable TeV-scale resonant leptogenesis, linking baryogenesis to collider phenomenology.

Findings

Thermal evolution of baryon asymmetry matches experimental data.

Model predicts same-sign dilepton signatures at colliders.

Incorporates keV dark matter candidate and TeV-scale RHNs.

Abstract

We explore an anomaly-free ${\textrm U}(1)$ gauge extended beyond the Standard model (BSM) framework, to account for the baryon asymmetry of the Universe, along with arranging for tiny neutrino mass. Neutrino masses are generated via higher-dimensional operators (HDOs) involving three right-handed neutrinos (RHNs) with gauge charges ($4$, $4$ and $-5$ respectively) and two BSM scalars. This is an attractive framework as it can accommodate a keV scale dark matter, with the lightest RHN being the candidate. The remaining two RHNs are quasi-degenerate at the TeV-scale, actively participating in the process of resonant leptogenesis through their decay governed by the same set of HDOs. The RHNs being at the TeV scale, make this framework relevant for studying flavored resonant leptogenesis. This TeV-scale resonant leptogenesis, after satisfying the neutrino oscillation data, leads to interesting predictions on the Yukawa sector of the model HDOs. The thermal evolution of the baryon asymmetry has followed the experimental results rather accurately in that corner of parameter space. As a matter of fact, this TeV-scale framework which in principle relies on the low scale resonant leptogenesis typically leads to predictions that potentially can be tested at the colliders. In particular, we consider the same-sign dilepton signature that arises from the RHN pair production through the decay of heavy gauge boson of the extra ${\textrm U}(1)$.