NSI can improve LMA predictions: neutrino decay in solar matter?

Abstract

We investigate the prospects for non-standard interactions (NSI) in solar neutrino propagation and detection and find that these may solve the tension between the observed flatness of the SuperKamiokande electron spectrum and its LMA prediction which has a clear negative slope. Also the Cl rate prediction from NSI comes within 1$\sigma$ of its experimental value instead of the LMA one which lies more than 2$\sigma$ above. A remarkable consequence of NSI for solar neutrinos is the possibility of neutrino decay into majorons and antineutrinos whose appearance probability is calculated but found to be rather small.