Exploring the relative polarization of two photons from para-positronium decays using GEANT4 simulation toolkit.

Abstract

Quantum Electrodynamics (QED) is an example of success of Quantum Field theory. A positronium atom is a bound state of an electron and positron, which decays to two, three or higher multiplicity of the photons. Being a purely leptonic system, positronium provides a very clean probe for testing the accuracy of QED calculations. Studying the photons from the decay of positronium provides a possibility to search for physics beyond the Standard Model as well as plays a crucial role in medicine and biology also to diagnose the healthiness of the tissue material. In this thesis we have focused on studying some of the crucial aspects of detection of the photons from the positronium decay using the GEANT4 simulation toolkit. Our studies include the mechanisms by a which a sub MeV range photon deposit its energy in the material, energy resolution and efficiency of the detectors and measuring the polarization of a photon in an experimental setup.