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Leptogenesis During an Era of Early SU(2) Confinement

High Energy Physics - Phenomenology 2025-10-10 v1 High Energy Physics - Theory

Abstract

We explore leptogenesis during a cosmological epoch during which the electroweak SU(2)LSU(2)_L force is confined. During weak confinement, there is only one conserved non-anomalous global charge, rr, which is a linear combination of lepton-number, baryon-number, and hypercharge. The inclusion of heavy Majorana neutrinos leads to an rr-charge and CPCP-violating interaction, allowing for the generation of an rr-charge asymmetry, which translates into a baryon asymmetry post SU(2)LSU(2)_L deconfinement. Determining the resulting baryon asymmetry as a function of the model parameters, we find that the predicted baryon-asymmetry can match observations for a wide swath of parameter space. While leptogenesis under the assumption of a standard cosmology relies on the complex phase of the neutrino Yukawa couplings, the asymmetry generated in this novel background cosmology primarily depends on a strong phase from SU(2)LSU(2)_L confinement and favors negligible CPCP-violation in the right-handed neutrino decays.

Keywords

Cite

@article{arxiv.2503.09723,
  title  = {Leptogenesis During an Era of Early SU(2) Confinement},
  author = {India Bhalla-Ladd and Izzy Ginnett and Tim M. P. Tait},
  journal= {arXiv preprint arXiv:2503.09723},
  year   = {2025}
}