About Us

Our laboratory leads the BASE collaboration at CERN’s Antiproton Decelerator and ELENA facility, where we conduct ultra-high-precision experiments to compare the fundamental properties of protons and antiprotons. These studies utilize advanced cryogenic multi-Penning trap systems and have led to several record-breaking results. 

Notably, our comparison of the proton and antiproton charge-to-mass ratio—achieved with an unprecedented precision of 16 parts per trillion (Nature, 2024)—currently stands as the most accurate test of fundamental charge, parity, and time-reversal (CPT) symmetry in the baryon sector. We have also measured the magnetic moments of the proton and antiproton with a fractional precision of 1.5 parts per billion, providing another stringent test of matter-antimatter symmetry (Nature, 2017).

Our work is enabled by a range of technological innovations. We have developed antiproton reservoir traps capable of storing antiprotons for several years (Nature, 2019), allowing high-precision experiments even during accelerator shutdowns. Our systems operate Penning traps with the lowest demonstrated quantum heating rates (PhyRevLett, 2013), employ extreme magnetic field gradients, and feature world-leading detection technologies (S.Ulmer). These tools have enabled us to place tight constraints on exotic physics scenarios, including stringent bounds on the parameter space for millicharged dark matter (PRXQuantum,2022) and asymmetric antimatter-dark matter interactions (Nature,2019).

One of our latest achievements is the development of transportable antiproton traps. As part of the BASE-STEP project, we recently demonstrated the successful extraction and transport of protons from CERN’s antimatter factory. Our long-term vision is to transition high-precision antimatter spectroscopy to quieter, offline laboratory environments. These setups will allow for measurements at even higher accuracies—advancing our understanding of one of the most profound questions in modern physics: the observed dominance of matter over antimatter in the universe.

At Heinrich Heine University Düsseldorf, we are currently establishing an ultra-low-noise laboratory to support this next-generation, transformative antiproton spectroscopy program.