Impact of the first SNO results on Neutrino Mass and Mixing

Abstract

We investigate the implications of the SNO charged-current (CC) and electron scattering (ES) measurements of solar $^8B$ neutrino fluxes for neutrino mass and mixing parameters by performing a global and unified $\\chi^2$ analysis of the solar neutrino data incorporating the first SNO results along with the results from Cl, Ga and SuperKamiokande(SK) on the total flux of neutrinos as well as the recoil electron spectrum observed at SK and the CC spectrum observed at SNO in the framework of two neutrino mixing. We determine the best-fit values of the parameters, the $\\chi^2_{min}$ and the goodness of fit of various oscillation solutions for both $\\nu_{e} - \\nu_{active}$ and $\\nu_{e} - \\nu_{sterile}$. We present the allowed regions in the parameter space of neutrino mass and mixing with respect to the global minimum for $\\nu_e - \\nu_{active}$. We compare our results with those obtained pre-SNO to highlight the impact of the SNO results.