Sub-GeV dark matter as pseudo-Goldstone from the seesaw scale
Abstract
Pseudo Nambu-Goldstone bosons (pNGBs) are naturally light spin-zero particles, which can be interesting dark matter (DM) candidates. We study the phenomenology of a pNGB theta associated with an approximate symmetry of the neutrino seesaw sector. A small coupling of theta to the Higgs boson is induced radiatively by the neutrino Yukawa couplings. By virtue of this Higgs portal interaction (i) the pNGB acquires a mass m_theta proportional to the electroweak scale, and (ii) the observed DM relic density can be generated by the freeze-in of theta-particles with mass m_theta ~ 3 MeV. Alternatively, the coupling of theta to heavy sterile neutrinos can account for the DM relic density, in the 1 keV-3 MeV window. The decays of theta into light fermions are suppressed by the seesaw scale, making such pNGB sufficiently stable to play the role of DM.
Keywords
Cite
@article{arxiv.1107.4564,
title = {Sub-GeV dark matter as pseudo-Goldstone from the seesaw scale},
author = {Michele Frigerio and Thomas Hambye and Eduard Masso},
journal= {arXiv preprint arXiv:1107.4564},
year = {2013}
}
Comments
30 pages, 4 figures, version to appear in Phys. Rev. X (Fig. 2 slightly modified, references added)