Oscillation enhanced search for new interactions with neutrinos

We discuss the measurement of new physics in long baseline neutrino oscillation experiments. Through neutrino oscillations, the probability to detect new physics effects such as flavor violation is enhanced by interference with the weak interaction. We carefully explain the situations in which interference can take place. Assuming a neutrino factory and an upgraded conventional beam, we estimate the feasibility to observe new physics numerically and point out that we can search new interactions using some channels, for example, ${\nu }_{\mu }\to {\nu }_{\mu },$ in these experiments. We also discuss several models which induce effective interactions interfering with the weak interaction, and show that some new physics effects are large enough to be observed in an oscillation enhanced way.