Probing CP symmetry in Xi, Lambda hyperon decays.

   The HyperCP, FNAL E871, experiment has been designed to probe
CP conservation in hyperon decays. We study the distribution
of the proton in the decay sequence Xi- -> Lambda pi-, Lambda -> p pi-,
and of the anti-proton in the charge conjugate decays.
Any observed asymmetry between the distributions would result
from direct CP violation in the decays.
   Data was collected during the last two 800-GeV fixed-target
runs at Fermilab. We have fully reconstructed more than two billion
hyperon decays for the measurement. This will allow us to establish
the CP asymmetry with  a statistical sensitivity better than 2 x 10^-4.
Preliminary results based on a several percent of the data will be presented.