Neutrino decay confronts the SNO data

We investigate the status of the neutrino decay solution to the solar neutrino problem in the context of the recent results from Sudbury Neutrino Observatory (SNO). We present the results of global chi(2)-analysis for both two and three generation cases with one of the mass states being allowed to decay and include the effect of both decay and mixing. We find that the Large Mixing Angle (LMA) region which is the currently favoured solution of the solar neutrino problem is affected significantly by decay. We present the allowed areas in the Deltam(2)-tan(2) theta plane for different allowed values of alpha and examine how these areas change with the inclusion of decay. We obtain bounds on the decay constant a in this region which implies a rest frame life time tau(0)/m(2) > 8.7 x 10(-5) s/eV for the unstable neutrino state. We conclude that the arrival of the neutral current results from SNO further disfavors the neutrino decay solution to the solar neutrino problem leaving a very small window for the decay constant alpha which could still be allowed. (C) 2003 Elsevier Science B.V. All rights reserved.