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Title: Dark matter in the minimal inverse seesaw mechanism

Journal Article · · Journal of Cosmology and Astroparticle Physics
;  [1];  [2]
  1. Laboratoire de Physique Théorique, Université de Paris-Sud 11, Bât. 210, 91405 Orsay Cedex (France)
  2. Institute for theoretical physics, Georg-August University Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077 Germany (Germany)

We consider the possibility of simultaneously addressing the dark matter problem and neutrino mass generation in the minimal inverse seesaw realisation. The Standard Model is extended by two right-handed neutrinos and three sterile fermionic states, leading to three light active neutrino mass eigenstates, two pairs of (heavy) pseudo-Dirac mass eigenstates and one (mostly) sterile state with mass around the keV, possibly providing a dark matter candidate, and accounting for the recently observed and still unidentified monochromatic 3.5 keV line in galaxy cluster spectra. The conventional production mechanism through oscillation from active neutrinos can account only for ∼ 43% of the observed relic density. This can be slightly increased to ∼ 48% when including effects of entropy injection from the decay of light (with mass below 20 GeV) pseudo-Dirac neutrinos. The correct relic density can be achieved through freeze-in from the decay of heavy (above the Higgs mass) pseudo-Dirac neutrinos. This production is only effective for a limited range of masses, such that the decay occurs not too far from the electroweak phase transition. We thus propose a simple extension of the inverse seesaw framework, with an extra scalar singlet coupling to both the Higgs and the sterile neutrinos, which allows to achieve the correct dark matter abundance in a broader region of the parameter space, in particular in the low mass region for the pseudo-Dirac neutrinos.

OSTI ID:
22375851
Journal Information:
Journal of Cosmology and Astroparticle Physics, Vol. 2014, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
Country of Publication:
United States
Language:
English