On the effect of θ13 on the determination of solar oscillation parameters at KamLAND

If the solution to the solar neutrino puzzle falls in the LMA region, KamLAND should be able to measure with good precision the corresponding oscillation parameters after a few years of data taking. Assuming a positive signal, we study their expected sensitivity to the solar parameters (θ12,Δm221) when considered in the framework of three-neutrino mixing after taking into account our ignorance on the mixing angle θ13. We find a simple “scaling” dependence of the reconstructed θ12 range with the value of θ13 while the Δm212 range is practically unaffected. Our results show that the net effect is approximately equivalent to an uncertainty on the overall neutrino flux normalization of up to ∼10%.