Light Sterile Neutrino in the Minimal Extended Seesaw

Physics Letters B (Impact Factor: 6.02). 10/2011; 714(2-5). DOI: 10.1016/j.physletb.2012.06.074
Source: arXiv

ABSTRACT Motivated by the recent observations on sterile neutrinos, we present a
minimal extension of the canonical type-I seesaw by adding one extra singlet
fermion. After the decoupling of right-handed neutrinos, an eV-scale mass
eigenstate is obtained without the need of artificially inserting tiny mass
scales or Yukawa couplings for sterile neutrinos. In particular, the
active-sterile mixing is predicted to be of the order of 0.1. Moreover, we show
a concrete flavor A_4 model, in which the required structures of the minimal
extended seesaw are realized. We also comment on the feasibility of
accommodating a keV sterile neutrino as an attractive candidate for warm dark

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