English

Leptogenesis with perturbations in type-II and type-III seesaw models

High Energy Physics - Phenomenology 2025-05-27 v3 Cosmology and Nongalactic Astrophysics

Abstract

Density perturbations have recently been shown to lead to a novel effect in the freeze-out of heavy particles called "acoustically driven freeze-out." This leads to an enhancement in the yield in standard leptogenesis. We extend this calculation to include 222 \to 2 washout processes in type-I leptogenesis and the Sommerfeld-enhanced 222 \to 2 gauge annihilations in type-II and type-III leptogenesis. These CP conserving gauge annihilations suppress the yield of heavy particles sourcing the asymmetry. We show the acoustically driven freeze-out leads to novel enhancements in the baryon asymmetry in type-II and type-III leptogenesis, already in the weak washout regime, in contrast with type-I leptogenesis.

Keywords

Cite

@article{arxiv.2503.02936,
  title  = {Leptogenesis with perturbations in type-II and type-III seesaw models},
  author = {Iason Baldes},
  journal= {arXiv preprint arXiv:2503.02936},
  year   = {2025}
}

Comments

9 pages, 3 figures, comments begrudgingly welcomed. v2: small corrections, references added. v3: minor comments added