CP violation in strange baryon decays: A report from Fermilab experiment 871

Abstract

Fermilab experiment 871, HyperCP, is a search for direct CP violation in Ξ and Λ hyperon decays. A non-zero value in the asymmetry parameter A, defined in terms of the decay parameter products αΞαΛαΞαΛ and ,αΞ̄αΛ̄, would be unambiguous evidence for direct CP violation. The first data-taking run finished at the end of 1997 and accumulated over one billion Ξ−Ξ− and +Ξ̄+ decays. A sensitivity in A of ≈ 10−4≈10−4 is expected. A review of CP violation in hyperon decays is given, the HyperCP detector is described, and the status of the data analysis is discussed. © 1999 American Institute of Physics.