Being governed by electromagnetic interaction, the bound state of electron and positron forms a metastable state-Positronium. Test for bound state QED could be carried out by probing the decay rates of Positronium. In particular the Ps triplet state, the ortho-Positronium, which predominantly decays into three gamma quanta. Based on QED calculations, the rate for oPs decaying into a higher number of photons is by six orders of magnitude smaller compared to 3gamma decay.
However, higher decay channels could be probed using the multi-purpose Jagiellonian PET (J-PET) detector. J-PET is a plastic-scintillator based, multi-discipilinary PET tomograph extending its reach from biomedical application to active fundamental studies like CPT invariance, photon entanglement and mirror matter searches.
In this work we will present the capabilities of J-PET and preliminary studies of the multi-photon decays of oPs and aim to put stringent limits in this rare decay.