Contrasting solar and reactor neutrinos with a non-zero value of theta13

Abstract

When solar neutrino and KamLAND data are analyzed separately one finds that, even though allowed regions of neutrino parameters overlap, the values of $\delta m^2$ and the mixing angle $\theta_{12}$ at the $\chi^2$ minima are different. We show that a non-zero, but small value of the angle $\theta_{13}$ can account for this behavior. From the joint analysis of solar neutrino and KamLAND data we find the best fit value of $\sin^2 2 \theta_{13} = 0.01 ^{-0.01}_{+0.09}$.