Schematic Method for Estimation of CP Asymmetry in Neutrino Oscillation

Within the framework of three generations of leptons the schematical method for estimating CP asymmetry in neutrino oscillations is considered. We introduce a unitarity triangle corresponding to \nu_e-\nu_{\mu} oscillation, in addition, we show that it is convenient for the estimation to define another new triangle. CP asymmetry is determined by the difference between the shapes of a unitarity triangle and new triangle. As results, (i) we show that CP asymmetry becomes maximal if the shapes of these two triangles are the same. (ii) We can easily estimate L/E which leads almost 100% asymmetry using this. (iii) In \nu_e-\nu_{\mu} oscillation with \sin^2 2\theta_{13} \simeq 0.04, we obtain about 90% asymmetry for LMA MSW scenario and 3% asymmetry for SMA MSW scenario within long baseline neutrino expriments to be realized in near future.