Annihilating Leptogenesis

TL;DR

This paper proposes a novel leptogenesis mechanism via annihilations of heavy particles, extending the standard model with additional scalars, and demonstrates its compatibility with fundamental theories like GUTs.

Contribution

It introduces a new leptogenesis scenario based on particle annihilations, expanding beyond the traditional decay-based models, and shows its integration with broader theoretical frameworks.

Findings

Demonstrates viability of annihilating leptogenesis in extended standard model

Shows compatibility with left-right symmetric models and GUTs

Provides a realistic model with heavy doublet and light singlet scalars

Abstract

Leptogenesis is usually realized through decays of heavy particles. In this article we consider another possibility of generating a lepton asymmetry through annihilations of heavy particles. We demonstrate our idea with a realistic extension of the standard model containing a heavy doublet and a light singlet scalars in addition to right-handed neutrinos and Higgs triplets required for type-I+II seesaw of neutrino masses. We also clarify that this annihilating leptogenesis scenario can be naturally embedded in more fundamental theories, like left-right symmetric models or grand unified theories.