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) less than or similar to Deltam(21)(2) less than or similar to 10(-4) eV(2) and oscillation amplitude sin(2)2 theta (12) > 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 Deltam(21)(2) to approximately +/-10% (for sin(2) 2 theta (12) > 0.7) and to fix sin(2) 2 theta (12) to within +/-0.1 (at the 3 sigma level) with three years of accumulated data, independent of the value of theta (13) (C) 2001 Published by Elsevier Science B.V.