Relic gravity waves and 7 keV dark matter from a GeV scale inflaton
2014; Elsevier BV; Volume: 736; Linguagem: Inglês
10.1016/j.physletb.2014.07.060
ISSN1873-2445
AutoresFedor Bezrukov, Dmitry Gorbunov,
Tópico(s)Particle physics theoretical and experimental studies
ResumoWe study the mechanism of generation of 7 keV sterile neutrino Dark Matter (DM) in the model with light inflaton $χ$, which serves as a messenger of scale invariance breaking. In this model the inflaton, in addition to providing reheating to the Standard Model (SM) particles, decays directly into sterile neutrinos. The latter are responsible for the active neutrino oscillations via seesaw type I like formula. While the two sterile neutrinos may also produce the lepton asymmetry in the primordial plasma and hence explain the baryon asymmetry of the Universe, the third one being the lightest may be of 7 keV and serve as DM. For this mechanism to work, the mass of the inflaton is bound to be light (0.1-1 GeV) and uniquely determines its properties, which allows to test the model. For particle physics experiments these are: inflaton lifetime ($10^{-5}-10^{-12}$ s), partial decay width of B-meson to kaon and inflaton ($10^{-6}-10^{-4}$) and inflaton branching ratios into light SM particles like it would be for the SM Higgs boson of the same mass. For cosmological experiments these are: spectral index of scalar perturbations ($n_s\simeq0.957-0.967$), and amount of tensor perturbations produced at inflation (tensor-to-scalar ratio $r\simeq0.15-0.005$).
Referência(s)