Seesaw right-handed neutrino as the sterile neutrino for LSND

Abstract

We show that a double seesaw framework for neutrino masses with µ − τ exchange symmetry can lead to one of the righthanded seesaw partners of the light neutrinos being massless. This can play the role of a light sterile neutrino, giving a 3 + 1 model that explains the LSND results.We get a very economical scheme, which makes it possible to predict the full 4 × 4 neutrino mass matrix if CP is conserved. Once CP violation is included, effect of the LSND mass range sterile neutrino is to eliminate the lower bound on neutrinoless double beta decay rate which exists for the three neutrino case with inverted mass hierarchy. The same strategy can also be used to generate a natural 3 + 2 model for LSND, which is also equally predictive for the CP conserving case in the limit of exact µ − τ symmetry.

A White Paper on keV sterile neutrino Dark Matter

“…In this case, for |µ S | |m N |, |m D |, it is possible to have very light sterile neutrinos, e.g. in the presence of a µ − τ symmetry [770] or in theories with warped extra dimensions [771].…”

Nonzeroθ13with unbrokenμ−τsymmetry of the active neutrino mass matrix in the presence of a light sterile neutrino

“…Another interesting but much less explored idea to generate non-zero θ 13 is by allowing the mixing of three active neutrinos with a eV scale sterile neutrino [25][26][27][28]. For a review of light 2 For a recent review, please see [13].…”

Light and superlight sterile neutrinos in the minimal radiative inverse seesaw model

“…with respect to the set of variables {θ 34 , θ 35 , θ 45 , θ 46 , θ 56 } while requiring that the elements U τ i for i = 1, 2, 3 lie within the allowed range given in (22). For illustration, our results for x R = 1 case are shown in Fig.…”

“…To achieve this, we minimize the function defined in (30) while simultaneously requiring that the elements |U τ i | for i = 1, 2, 3 fall within the allowed range of |V τ 3 | given in (22). In addition, we require that the element |U s33 | 2 should • , θ 35 = 10.8 …”

“…In this case, for µ S M N , M D , it is possible to have very light sterile neutrinos, e.g. in the presence of a µ − τ symmetry [22] or in theories with warped extra dimensions [23].…”