MiniBooNE results and neutrino schemes with 2 sterile neutrinos: possible mass orderings and observables related to neutrino masses

Abstract

The MiniBooNE and LSND experiments are compatible with each other when two sterile neutrinos are added to the three active ones. In this case there are eight possible mass orderings. In two of them both sterile neutrinos are heavier than the three active ones. In the next two scenarios both sterile neutrinos are lighter than the three active ones. The remaining four scenarios have one sterile neutrino heavier and another lighter than the three active ones. We analyze all scenarios with respect to their predictions for mass-related observables. These are the sum of neutrino masses as constrained by cosmological observations, the kinematic mass parameter as measurable in the KATRIN experiment, and the effective mass governing neutrinoless double beta decay. It is investigated how these non-oscillation probes can distinguish between the eight scenarios. Six of the eight possible mass orderings predict positive signals in the KATRIN and future neutrinoless double beta decay experiments. We also remark on scenarios with three sterile neutrinos. In addition we make some comments on the possibility of using decays of high energy astrophysical neutrinos to discriminate between the mass orderings in presence of two sterile neutrinos. *

Predictions for neutrinoless double-beta decay in the 3+1 sterile neutrino scenario

“…[13,[25][26][27][28][29][30][31][32][33]. Our paper improves these discussions by taking into account the uncertainties of all the mixing parameters and presenting all the results at 1σ, 2σ and 3σ.…”

“…The introduction of a sterile neutrino at the eV mass scale can change dramatically the prediction for the possible range of values for the effective Majorana mass in neutrinoless double-beta decay [13,[25][26][27][28][29][30][31][32][33]. In this paper we present accurate predictions for |m ββ | taking into account the results of the global fit of solar, atmospheric and long-baseline reactor and accelerator neutrino oscillation data presented in ref.…”

Light sterile neutrinos

“…Many analyses of short-baseline neutrino oscillation data have been done since the discovery of the LSND anomaly in the middle 90's [80,81,83,88,90,91,93,[165][166][167][168][169][170][171][172][173][174][175][176][177][178].…”

Neutrino-Less Double Beta Decay and Particle Physics

“…In fact, the difference between MiniBooNE's neutrino and antineutrino results can be explained by two additional eV-like ∆m 2 plus CP violation. Here one could envisage 2+3 or 3+2 scenarios, in which 2 sterile neutrinos lie above or below the three active ones, or 1+3+1 scenarios 126 , in which one sterile neutrino is heavier than the three active ones and the other sterile neutrino is lighter. Recently, reactor neutrino fluxes have been re-evaluated and an underestimation of 3% with respect to previous results has been found 127 .…”

“…126 . The new sterile neutrinos will contribute to the sum of masses in cosmology, to the kinematic mass in KATRIN, and, if they are Majorana particles, to 0νββ.…”