Resolving the solar neutrino problem with KamLAND

We study how well KamLAND, the first terrestrial neutrino experiment capabl e of addressing the solar neutrino problem, will perform in ascertaining wh ether 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 oscillati on amplitude sin(2)2 theta (12) > 0.3) is correct. We find that in a year o f operation KamLAND will provide unequivocal evidence for or against this s olution. Furthermore, its sensitivity to the three-neutrino oscillation par ameters 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 acc umulated data, independent of the value of theta (13) (C) 2001 Published by Elsevier Science B.V.