Sterile neutrinos in the 3+s scenario and solar data

Abstract

The flatness of the SuperKamiokande neutrino electron scattering spectrum and the apparent downturn of the charged current spectrum in the SNO data which the Large Mixing Angle solution (LMA) to the solar neutrino problem fails to predict are analysed in the context of an extension to the standard electroweak model with light sterile neutrinos. It is found that a sterile neutrino which is quasi degenerate with the active ones with $\Delta m^2_{41}=10^{-5}eV^2$ and mixing $sin\theta_{14}=0.04$ provides a suitable improvement to the LMA data fits.