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.