Feasibility studies for imaging e$^{+}$e$^{-}$ annihilation with modular multi-strip detectors

TL;DR

This study explores the use of modular multi-strip detectors for imaging positron-electron annihilation, aiming to enable applications in nuclear medicine, fundamental physics, and tests of Einstein's equivalence principle.

Contribution

It presents the first feasibility assessment of modular multi-strip detectors for imaging e$^{+}$e$^{-}$ annihilations, evaluating their performance for gravitational studies of positronium.

Findings

Detectors demonstrated promising spatial resolution for annihilation imaging.

Feasibility confirmed for using these detectors in fundamental physics experiments.

Potential for application in inertial sensing and tests of gravity with positronium.

Abstract

Studies based on imaging the annihilation of the electron (e$^{-}$) and its antiparticle positron (e$^{+}$) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the direct conversion of e$^{+}$e$^{-}$ into photons and the formation of their atomically bound state, the positronium atom (Ps), which can be used as a probe for fundamental studies. With the ability to produce large quantities of Ps, manipulate them in long-lived Ps states, and image their annihilations after a free fall or after passing through atomic interferometers, this purely leptonic antimatter system can be used to perform inertial sensing studies in view of a direct test of Einstein equivalence principle. It is envisioned that modular multistrip detectors can be exploited as potential detection units for this kind of studies. In this work, we report the results of the first feasibility study performed on a e$^{+}$ beamline using two detection modules to evaluate their reconstruction performance and spatial resolution for imaging e$^{+}$e$^{-}$ annihilations and thus their applicability for gravitational studies of Ps.