Test of CPT symmetry with positronium at the J-PET detector

The Jagiellonian Positron Emission Tomograph (J-PET) is the first tomograph built from plastic scintillators capable to test CPT symmetry in decays of positronium atoms. This test is performed via determination of the expectation value of operators that are odd under discrete symmetries. The J-PET detector is optimized for the registration of photons from electron–positron annihilations, and such operators may be constructed from the spin of ortho-positronium atoms and the momenta and polarization vectors of photons originating from its annihilation