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.

中文翻译：

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存在非标准相互作用和参数简并的低能量长基线实验中的中微子振荡

我们讨论了在存在非标准相互作用 (NSI) 的情况下低能量长基线实验（例如 T2HK 和 T2HKK）中振荡概率的解析表达式。我们表明这些实验有利于探索 NSI 参数 ($\epsilon_D$, $\epsilon_N$)，这些参数被认为是非零的，以解释太阳中微子和 KamLAND 数据之间的差异。我们还表明，当 NSI 参数较小时，CP 阶段 $\delta$、$\epsilon_D$ 和 $\epsilon_N$ 中的参数退化可以通过结合 T2HK 和 T2HKK 实验的数据来解决。