Search for CP Violation in Ξ and Λ Hyperon Decays with the HyperCP Spectrometer at Fermilab

The HyperCP Collaboration at Fermilab is searching for CP violation in charged hyperon decays by comparing the angular decay distributions of protons and antiprotons from Ξ−→Λπ−, Λ→pπ− and , decays. Using a hyperon data sample orders of magnitude larger than any other experiment has collected, we report a preliminary result AΞΛ=[−6.0±2.1(stat)±2.0(syst)]×10−4, from an analysis of the entire HyperCP data set of over one billion events.