Search for CP Violation in Charged-Xi and Lambda Hyperon Decays

Abstract

We have compared the proton and antiproton angular distributions in 117 million Xi-minus -> Lambda + pi-minus -> proton + pi-minus + pi-minus and 41 million anti-Xi-minus -> anti-Lamba + pi-plus -> antiproton + pi-plus + pi-plus decays using a subset of the data from the HyperCP experiment (E871) at Fermilab. We find no evidence of CP violation, with the direct-CP-violating parameter $A_{\hat{I}ž\hat{I}›}=\frac{\hat{I}{\pm }_{\hat{I}}ž\hat{I}{\pm }_{\hat{I}}›-\bar{\hat{I}}{\pm }_{\hat{I}}ž\bar{\hat{I}}{\pm }_{\hat{I}}›}{\hat{I}{\pm }_{\hat{I}}ž\hat{I}{\pm }_{\hat{I}}›+\bar{\hat{I}}{\pm }_{\hat{I}}ž\bar{\hat{I}}{\pm }_{\hat{I}}›}=[0.0+/-5.1(stat)+/-4.4(syst)]\times 10^{-4}$.

4 pages, 4 figures, to be published in Phys. Rev. Lett