Probing nonstandard neutrino physics by two identical detectors with different baselines

The Kamioka-Korea two-detector system is a powerful experimental setup for resolving neutrino parameter degeneracies and probing CP violation in neutrino oscillation. In this paper, we study sensitivities of the same setup to several nonstandard neutrino physics such as quantum decoherence, tiny violation of Lorentz symmetry, and nonstandard interactions of neutrinos with matter. We show that it can achieve significant improvement on the current bounds on nonstandard neutrino physics. In most cases, the Kamioka-Korea two-detector setup is more sensitive than the one-detector setup, either in Kamioka or in Korea, except for the cases when Lorentz symmetry is broken in a CPT-violating manner and the nonstandard neutrino interactions with matter is present.