Parameter limits for neutrino oscillation with decoherence in KamLAND

In the framework of open quantum systems, we analyze data from KamLAND by using a model that considers neutrino oscillation in a three-family approximation with the inclusion of the decoherence effect. Using a χ2 test, we find new limits for the decoherence parameter, which we call γ, considering the most recent data by KamLAND. Assuming an energy dependence of the type γ=γ0(E/E0)n, at a 95% C.L., the limits found are 3.7×10−24 GeV for n=−1, 6.8×10−22 GeV for n=0, and 1.5×10−19 GeV for n=1 on the energy dependence.