Time reversal in polarized neutron decay: the emiT experiment

The standard electro-weak model predicts negligible violation of time-rever sal invariance in light quark processes. We report on an experimental test of time-reversal invariance in the beta decay of polarized neutrons as a se arch for physics beyond the standard model. The emiT collaboration has meas ured the time-reversal-violating triple-correlation in neutron beta decay b etween the neutron spin, electron momentum, and neutrino momentum often ref erred to as the D coefficient. The first run of the experiment produced 14 million events which are currently being analyzed. However, a second run wi th improved detectors should provide greater statistical precision and redu ced systematic uncertainties. (C) 2000 Elsevier Science B.V. All rights res erved.