  We evaluate the size of a coupling for a lepton flavor violating interaction
with neutrinos (nLFV) in the minimal supersymmetric standard model with
right-handed neutrinos (MSSMRN). It is expected that the nLFV interactions are
detected in a long baseline neutrino oscillation experiment. We here deal with
$\mu^{-} \to e^{-} \bar{\nu}_{e} \nu_{\tau}$ in $\nu_{\mu} \to \nu_{\tau}$
channel at a neutrino factory. First, we show the numerical study on
feasibility to observe such interaction and point out that we can search for
them with some oscillation channels. Next, we make a numerical calculation for
the size of the nLFV coupling in the framework of the MSSMRN. A long baseline
experiment is sensitive not only to the lepton mixings in the standard model
but also to new physics effect.
