KamLAND potentiality on the determination of Neutrino mixing parameters in the post SNO-NC era

We study in detail the power of the reactor experiment kamLAND for discriminating existing solutions to the SNP and giving accurate information on neutrino masses and mixing angles. Assuming the expected signal corresponding to various “benchmark” points in the 2 dimensional (∆m2, tan2 θ) mixing plane, we develop a full-fledged χ2 analysis which include KamLAND spectrum and all the existing solar evidence. A complete modelling of statistical and known systematics errors for 1 and 3 years of data taking is included, exclusion plots are presented. We find a much higher sensitivity especially for values of ∆m2 lying in the central part of the LMA region. The situation would be more complicate for values closer to the border of the LMA region (the so called HLMA region, i.e. ∆m2 ≤ 2 × 105 and ∆m2 ≥ 8 − 9 × 10−5 or tan2θ far from tan2 θ = 0.5). In this case kamLAND, with or without solar evidence, will be able only to select multiple regions in the parameter space, in the sense that different possible values of the parameters would produce the same signal.