First result on a new measurement of ε’/ε in the neutral-kaon system

Abstract

A new beam line and detector were constructed to increase statistical precision and greatly reduce systematic uncertainty on the ratio of the CP-nonconserving parameters \ensuremath{\epsilon}'/\ensuremath{\epsilon}. Major improve- ments are discussed together with a result from a first run: \ensuremath{\epsilon}'/\ensuremath{\epsilon}=0.0032\ifmmode\pm\else\textpm\fi{}0.0028 (statistical) \ifmmode\pm\else\textpm\fi{}0.0012 (systematic). The precision is better than earlier measurements yet the result is still consistent with the superweak mechanism (which predicts zero) and that due to Kobayashi and Maskawa. Significantly more data are being collected.