The FNAL experiment E773 has measured the phases Phi_{ +-} = (43.35 +- 0.70 +- 0.79) degree and Phi_{ 00}-Phi_{ +-} = (0.67 +- 0.85 +- 1.1) degree of the CP violating parameters eta_{ +-} and eta_{ 00} in the decay of neutral kaons into two charged or neutral pions. These preliminary results test CPT symmetry and show no evidence for a violation. In addition we present a preliminary measurement of Delta m = m_L - m_S = (0.5286 +- 0.0029 +- 0.0022)*E+10 hbar/sec and tau_S = (0.8929 +- 0.0014 +- 0.0014)*E-10 sec. The first errors are statistical and the second errors are systematic for above results.
Categories: hep-ex