Speaker
Description
Precision measurements to study strong-field Bound-State Quantum Electrodynamics (BSQED) involve systems that remain largely unexplored, and thus requires the use of new detection techniques. One paradigm lies in the spectroscopy of transitions between Rydberg states of exotic atoms [1].
The antiProtonic Atom X-ray spectroscopy (PAX) experiment aims to study such transitions in mid to high-Z antiprotonic atoms with novel x-ray/gamma microcalorimeter techniques [2]. Using an array of Transition Edge Sensors (TES) thermally coupled to an absorbing pixel, intrinsic resolutions (FWHM) of 50 eV at 100 keV can be achieved [3]. The PAX project applies this method for the first time with an antimatter beam, which presents a new experimental frontier.
Due to the high sensitivity of these detectors and their non-linearity, constructing a complete systematic calibration accounting for environment-related drifts in an antimatter environment is challenging. To address the experimental needs regarding detector response and event crosstalk characterization, we present a simulation-based approach as a possible path toward this goal. We recently started the development of a electro-thermal simulation featuring the full detector geometry to reproduce the measured data. I will show its implementation streamlined with a GEANT4 simulation that includes full event reconstruction from antiproton annihilation to induced TES signals.
[1] - N. Paul, et al., “Testing Quantum Electrodynamics with Exotic Atoms,” in Phys. Rev. Lett., vol. 126, no. 17, p. 173001, 2021.
[2] - G. Baptista, et al., “Towards Precision Spectroscopy of Antiprotonic Atoms for Probing Strong-field QED,” in Proceedings of International Conference on Exotic Atoms and Related Topics and Conference on Low Energy Antiprotons — PoS(EXA-LEAP2024). Austrian Academy of Sciences, Vienna.: Sissa Medialab, p. 085, 2025.
[3] - J. N. Ullom and D. A. Bennett, “Review of superconducting transition-edge sensors for x-ray and gamma-ray spectroscopy”, in Superconductor Science and Technology, vol. 28, no. 8, p.084003, 2015