Neutrino Oscillations at low energy long baseline experiments in the presence of nonstandard interactions and parameter degeneracy

We discuss the analytical expression of the oscillation probabilities at low energy long baseline experiments, such as T2HK and T2HKK in the presence of nonstandard interactions (NSIs). We show that these experiments are advantageous to explore the NSI parameters ($epsilon_D$, $epsilon_N$), which were suggested to be nonvanishing to account for the discrepancy between the solar neutrino and KamLAND data. We also show that, when the NSI parameters are small, parameter degeneracy in the CP phase $delta$, $epsilon_D$ and $epsilon_N$ can be resolved by combining data of the T2HK and T2HKK experiments.