J-PET detection modules based on plastic scintillators for performing studies with positron and positronium beams

TL;DR

The paper discusses the development and testing of the J-PET detector, a modular plastic scintillator system, for studying positronium decays, symmetry tests, and photon polarization entanglement.

Contribution

It introduces a new modular J-PET detector prototype with portable detection units for advanced positronium research.

Findings

Successful initial tests of the modular detection units

Potential for precision symmetry and entanglement studies

Compatibility with continuous positron beams

Abstract

The J-PET detector, which consists of inexpensive plastic scintillators, has demonstrated its potential in the study of fundamental physics. In recent years, a prototype with 192 plastic scintillators arranged in 3 layers has been optimized for the study of positronium decays. This allows performing precision tests of discrete symmetries (C, P, T) in the decays of positronium atoms. Moreover, thanks to the possibility of measuring the polarization direction of the photon based on Compton scattering, the predicted entanglement between the linear polarization of annihilation photons in positronium decays can also be studied. Recently, a new J-PET prototype was commissioned, based on a modular design of detection units. Each module consists of 13 plastic scintillators and can be used as a stand-alone, compact and portable detection unit. In this paper, the main features of the J-PET detector, the modular prototype and their applications for possible studies with positron and positronium beams are discussed. Preliminary results of the first test experiment performed on two detection units in the continuous positron beam recently developed at the Antimatter Laboratory (AML) of Trento are also reported.