Speaker
Description
The hyperons are produced with a non-zero spin polarization that is straight-forward to parameterize in processes involving virtual photons or vector mesons, enable direct and precise CP violation tests.
These CP tests can be performed on e.g. J/psi -> Lambda Lambdabar, J/psi-> Sigma Sigmabar, J/psi -> Xi Xibar and psi(2S) -> Omega Omegabar. For the Xi -> Lambda pi decay the exclusive measurement of the final state particles allows for three independent CP tests and the determination of the strong and weak phase differences. Thanks to the large datasets in the tau-mass region, including the world's largest data samples at the J/psi and psi(2S) resonances collected at the BESIII experiment, the multi-dimensional analyses making use of polarization and entanglement have been performed for these processes. In the presentation an outline of the methods and recent results achieved at BESIII will be discussed.
