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 ${\chi }^2$ test, we find new limits for the decoherence parameter, which we call $\gamma$, considering the most recent data by KamLAND. Assuming an energy dependence of the type $\gamma ={\gamma }_0{(E/E_0)}^n$, at a 95% C.L., the limits found are $3.7\times {10}^{-24}\mathrm{GeV}$ for $n=-1$, $6.8\times {10}^{-22}\mathrm{GeV}$ for $n=0$, and $1.5\times {10}^{-19}\mathrm{GeV}$ for $n=1$ on the energy dependence.

Figure 1

Confidence level curves for $n=0$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 2

Confidence level curves for $n=0$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 3

Confidence level curves for $n=0$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 4

Confidence level curves for $n=1$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 5

Confidence level curves for $n=1$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 6

Confidence level curves for $n=1$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 7

Confidence level curves for $n=-1$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 8

Confidence level curves for $n=-1$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 9

Confidence level curves for $n=-1$. The curves correspond to 68.27%, 90%, 95%, 99%, and 99.73% C.L.

Figure 10

Graph made with data from the simulation of our model for oscillation with decoherence considering best-fit values of the three parameters and the three different values for $n$ in the energy dependence. We also include the KamLAND data [11].