Testing Discrete Symmetries in Ortho-Positronium Decays with the J-PET Detector

A first result related to a CPT test in the decay of ortho-positronium based on data collected by means of the J-PET detector is already available, and a new test of CP symmetry is under investigation. Both results are based on the determination of angular correlations between momenta of gamma rays and other vector properties of the investigated system. Here, arguments for the possible usage of data collected by the J-PET group to test CPT symmetry within the Standard-Model Extension framework are shortly presented.