<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">CPT</mml:mi></mml:math>Tests in the Neutral Kaon System

Fermilab experiment E773 has measured the phases ${\ensuremath{\Phi}}_{+\ensuremath{-}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}43.53}^{\ensuremath{\circ}}\ifmmode\pm\else\textpm\fi{}{0.97}^{\ensuremath{\circ}}$ and ${\ensuremath{\Phi}}_{00}\ensuremath{-}{\ensuremath{\Phi}}_{+\ensuremath{-}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.62}^{\ensuremath{\circ}}\ifmmode\pm\else\textpm\fi{}{1.03}^{\ensuremath{\circ}}$ of the $\mathrm{CP}$ violating parameters ${\ensuremath{\eta}}_{+\ensuremath{-}}$ and ${\ensuremath{\eta}}_{00}$ from interference in the decay of neutral kaons into two charged or neutral pions from a pair of regenerators. New measurements of the ${K}_{L}$- ${K}_{S}$ mass difference and the ${K}_{S}$ lifetime are also given. These results test $\mathrm{CPT}$ symmetry and show no evidence for a violation.