Probing Strong-field QED with Highly Charged Ions and Exotic Atoms

by Nancy Paul (Laboratoire Kastler Brossel)


From dark matter and dark energy, to neutrino oscillations and the lack of antimatter in the universe, there is growing evidence that the Standard Model is incomplete. Tests of Quantum Electrodynamics (QED) with few-electron systems offer a promising avenue for looking for new physics, as QED is the best understood quantum field theory and extremely precise predictions can be obtained for few-electron systems. I will present our ongoing work for highest precision strong field QED tests with highly charged ions using the Paris Double Crystal spectrometer [1,2]. I will then describe a new, complementary method for strong field QED tests using exotic muonic and antiprotonic atoms, now possible with newly available quantum sensors for X-ray detection—Transition Edge Sensing (TES) microcalorimeter detectors [3]. Spectroscopy of Rydberg states in these systems offer the unique opportunity to attain strong electric field conditions while avoiding uncertainties associated with nuclear size uncertainties. I will then report on first measurements within this paradigm within the HEATES (Heavy Exotic Atoms with Transition Edge Sensors) collaboration at J-PARC in Japan [4], where we have measured transitions in muonic neon, and discuss future possibilities using antiprotonic atoms at CERN.

[1] P. Amaro et al, Radiation Physics and Chemistry 98 (2014) 132–149
[2] J. Machado et al, Physical Review A 101, 062505 (2020)
[3] N. Paul et al, Physical Review Letters
126, 173001 (2021)
[4] T. Okumura et al, Physical Review Letters 127, 053001 (2021)