Speaker
Description
Positronium (Ps), an exotic atom composed of an electron and a positron, is an ideal system for testing Quantum Electrodynamics (QED) and probing potential extensions of the Standard Model (SM), including dark matter candidates such as mirror matter. Mirror matter theories predict that ortho-positronium (o-Ps) could oscillate into an invisible mirror state, leading to deviations in its measurable lifetime. In this study, we present the ongoing search for such phenomena using the modular configuration of the Jagiellonian Positron Emission Tomograph (J-PET) [1]. This state-of-the-art detector employs plastic scintillators read out by silicon photomultipliers (SiPMs), achieving high timing an spatial resolution essential for precision positronium studies [2, 3, 4].
The experiment is conducted in vacuum conditions using XAD4 porous polymer [5] to enhance positronium formation. A dedicated Monte Carlo simulation framework, combined with advanced event reconstruction and background suppression techniques, is used to isolate three-photon o-Ps decays and determine their lifetimes with high precision. The goal of this research is to reach a sensitivity level of 106, enabling a stringent test of QED predictions and an indirect search for mirror matter signatures. The results will provide new constraints on hidden sector models and contribute to the broader effort to understand the nature of dark matter.
We acknowledge support from the National Science Centre of Poland through Grants No. 2019/35/B/ST2/03562, 2020/38/E/ST2/00112, and the SciMat and qLife Priority Research Area budget under the auspices of the program Excellence Initiative-Research University at Jagiellonian University.
References
[1] P. Moskal et al. Sci. Adv., 7:eabh4394, 2021.
[2] F. Tayefi et al. Bio-Algorithms Med-Syst., 19:133–139, 2023.
[3] P. Moskal et al. Sci. Adv., 10:adp2840, 2024.
[4] P. Moskal and E. Stępień. PET Clinics, 15(4):439–452, 2020.
[5] B. Jasińska et al. Acta Phys. Pol. A, 47(2):453, 2016.
