CP and T violation test in neutrino oscillation

I examine how large violation of CP and T is allowed in long base line neutrino experiments. When we attribute both the atmospheric neutrino anomaly and the solar neutrino deficit to neutrino oscillation we may have a sizable T violation effect proportional to the ratio of two mass differences; it is difficult to see CP violation since we can’t ignore the matter effect. I give a simple expression for T violation in the presence of matter. ∗e-mail address: [email protected]