Speaker
Description
The pronounced imbalance between matter and antimatter in the universe motivates high precision comparisons of fundamental properties of matter–antimatter conjugates. At CERN’s Antiproton Decelerator, the BASE collaboration performs such tests using cryogenic Penning traps. We have achieved the most precise proton–antiproton charge to mass ratio comparison to date, with a fractional uncertainty of 16 parts per trillion [1], and conducted the first direct high precision measurement of the antiproton magnetic moment with 1.5 ppb accuracy [2]. Combined with our proton magnetic moment measurement [3], these results improve magnetic moment–based CPT tests by more than a factor of 3000. In parallel, we are implementing new techniques for sympathetic cooling of antiprotons [4] and developing quantum logic–inspired spectroscopy methods [5]. We are also constructing the transportable antiproton trap BASE STEP to move precision antiproton measurements from CERN to dedicated laboratory space at Heinrich Heine University Düsseldorf [6]. In this talk, I will introduce the scientific context, report on the status of the first antiproton transport and discuss the progress towards an improved measurement of the antiproton magnetic moment using single particle methods in combination with phase sensitive cyclotron frequency detection to reach even higher precision. By making use of the recently demonstrated high coherence time of the antiproton spin [7], the goal is to do a coherent measurement on a single antiproton to improve the current best precision by at least two orders of magnitude.
[1] M. J. Borchert et al., Nature 601, 35 (2022).
[2] C. Smorra et al., Nature 550, 371 (2017).
[3] G. Schneider et al., Science 358, 1081 (2017).
[4] M. A. Bohman et al. Nature 596, 514 (2021).
[5] J. M. Cornejo et al., New J. Phys. 23 073045 (2022).
[6] M. Leonhardt et al., Nature 641, 871 (2026).
[7] B. M. Latacz et al., Nature 644, 64 (2026).