Resolving the solar neutrino problem with KamLAND

We study how well KamLAND, the first terrestrial neutrino experiment capable of addressing the solar neutrino problem, will perform in ascertaining whether or not the large mixing angle MSW solution (with 10−5≲Δm212≲10−4 eV2 and oscillation amplitude sin22θ12>0.3) is correct. We find that in a year of operation KamLAND will provide unequivocal evidence for or against this solution. Furthermore, its sensitivity to the three-neutrino oscillation parameters in this region is sufficiently acute as to determine Δm212 to approximately ±10% (for sin22θ12>0.7) and to fix sin22 θ12 to within ±0.1 (at the 3σ level) with three years of accumulated data, independent of the value of θ13.