Speaker
Description
The advent of quantum sensing x-ray microcalorimeters such as Transition Edge Sensors (TESs) [1] has created exciting new opportunities to push the limits of precision physics in the x-ray domain. Thanks to the factor of 50 improvement in energy resolution offered by TESs over high-purity germanium [2, 3], and their high efficiency compared to crystal spectrometers [4], anti-protonic atom x-ray spectroscopy has entered a new era compared to the previous generation of experiments. The PAX project (anti-Protonic Atom X-ray spectroscopy) will employ a next-generation TES detector for spectroscopy of Rydberg transitions in antiprotonic atoms to establish new benchmarks for bound-state QED with a precision of $10^{-5}$ at field strengths well beyond the Schwinger limit [5]. Details of the PAX experiment at the CERN’s ELENA facility [6], current status of detector development, and first results from test beam including unique challenges for detector development related to annihilation and electromagnetic background will be discussed.
References
[1] Review of superconducting transition-edge sensors for x-ray and gamma-ray spectroscopy, J.N. Ullom and D.A. Bennett. Supercond. Sci. Tech. 28, 084003 (2015).
[2] Recent Results on Antiprotonic Atoms using a Cyclotron Trap at LEAR, L.M. Simons. Physica Scripta 1988, 90 (1988).
[3] X-ray transitions from antiprotonic noble gases, D. Gotta, K. Rashid, B. Fricke, P. Indelicato and L.M. Simons. Eur. Phys. J D 47, 11-26 (2008).
[4] Balmer a transitions in antiprotonic hydrogen and deuterium, D. Gotta, D.F. Anagnostopoulos, M. Augsburger, G. Borchert, C. Castelli, D. Chatellard, J.P. Egger, P. El-Khoury, H. Gorke, P. Hauser, P. Indelicato, K. Kirch, S. Lenz, T. Siems and L.M. Simons. Nucl. Phys. A 660, 283-321 (1999).
[5] Testing Quantum Electrodynamics with Exotic Atoms, N. Paul, G. Bian, T. Azuma, S. Okada and P. Indelicato. Phys. Rev. Lett. 126, 173001 (2021).
[6] The ELENA facility, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, C. Carli, T. Eriksson, W. Oelert, R. Ostojic, S. Pasinelli and G. Tranquille. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, 20170266 (2018).
