Spontaneous Scoto-leptogenesis
Abstract
We propose a low-scale spontaneous leptogenesis scenario within the dynamical minimal scotogenic model for accommodating neutrino masses and inert scalar dark matter simultaneously. Thus, we dub the mechanism Spontaneous Scoto-leptogenesis. In this setup, a rolling Majoron arising from the global U(1)B−L symmetry breaking induces an effective chemical potential for the B−L charge in the presence of B−L violating interactions that allow for the efficient decays and inverse decays of right handed neutrinos (RHN) and RHN mediated scattering, so it gives rise to the observed baryon asymmetry of the Universe through the electroweak sphaleron conversion. The mechanism becomes effective in the strong washout regime and successfully lowers the viable mass scale of the lightest RHN to the range of TeV scales, thereby making the thermal scotogenic leptogenesis with two hierarchical RHNs accessible to direct tests. We identify the roles of the λ5 coupling for spontaneous leptogenesis and inert scalar dark matter through the efficient erasure of the inert scalar asymmetry. We also explore the regime for Majoron dark matter from the kinetic misalignment, showing that a multicomponent dark sector comprising the inert scalar and the Majoron can be realized in the model. The resulting framework provides a unified origin for low-scale baryogenesis, neutrino masses, and multicomponent dark sector, so it can be tested by complementary experimental probes through direct detection experiments, collider searches for inert scalars, and future detection of Majoron dark matter or dark radiation.
Related
BibTeX
@misc{datta2026spontaneous,
title = {{Spontaneous Scoto-leptogenesis}},
author = {Arghyajit Datta and Hyun Min Lee and Jun-Ho Song},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2608.12497},
eprint = {2608.12497},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.12497},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Spontaneous Scoto-leptogenesis
AU - Arghyajit Datta
AU - Hyun Min Lee
AU - Jun-Ho Song
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2608.12497
UR - https://arxiv.org/abs/2608.12497
AB - We propose a low-scale spontaneous leptogenesis scenario within the dynamical minimal scotogenic model for accommodating neutrino masses and inert scalar dark matter simultaneously. Thus, we dub the mechanism Spontaneous Scoto-leptogenesis. In this setup, a rolling Majoron arising from the global U(1)_B−L symmetry breaking induces an effective chemical potential for the B−L charge in the presence of B−L violating interactions that allow for the efficient decays and inverse decays of right handed neutrinos (RHN) and RHN mediated scattering, so it gives rise to the observed baryon asymmetry of the Universe through the electroweak sphaleron conversion. The mechanism becomes effective in the strong washout regime and successfully lowers the viable mass scale of the lightest RHN to the range of TeV scales, thereby making the thermal scotogenic leptogenesis with two hierarchical RHNs accessible to direct tests. We identify the roles of the λ_5 coupling for spontaneous leptogenesis and inert scalar dark matter through the efficient erasure of the inert scalar asymmetry. We also explore the regime for Majoron dark matter from the kinetic misalignment, showing that a multicomponent dark sector comprising the inert scalar and the Majoron can be realized in the model. The resulting framework provides a unified origin for low-scale baryogenesis, neutrino masses, and multicomponent dark sector, so it can be tested by complementary experimental probes through direct detection experiments, collider searches for inert scalars, and future detection of Majoron dark matter or dark radiation.
ER -