Determination of Re(ɛ’/ɛ) by the simultaneous detection of the four<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="italic">K</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">L</mml:mi><mml:mo>,</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math><i>S</i>→ππ decay modes

The E731 experiment at Fermilab has searched for direct CP violation in ${\mathit{K}}^{0}$\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi}, which is parametrized by \ensuremath{\varepsilon}'/\ensuremath{\varepsilon}. For the first time all four of the ${\mathit{K}}_{\mathit{L},}$S\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\pi} modes were collected simultaneously, which greatly facilitated studies of systematic uncertainty. We find Re(\ensuremath{\varepsilon}'/\ensuremath{\varepsilon})=-0.0004\ifmmode\pm\else\textpm\fi{}0.0014(stat)\ifmmode\pm\else\textpm\fi{}0.0006(syst). The result provides no evidence for direct CP violation.