Wave Packet Approach to Neutrino Oscillations with Matter Effects

The complete description of neutrino oscillations require the wave packet treatment. For terrestrial experiments the contribution from the interaction of neutrino with the Earth matter would modify oscillation pattern, i.e., the dependence of the flavor transition probability on baseline $L$ and energy $E$. We thus combine the wave packet approach and the matter effects, in order to have more accurate descriptions of neutrino oscillation. The general expression for the transition probability of oscillations with arbitrary numbers of neutrinos are derived. As an example the two-neutrino oscillation is studied in detail.