Antiproton transport system to take the Standard Model for a spin

A fundamental challenge to our current understanding of the universe lies in the asymmetry of matter and antimatter. The Standard Model cannot explain why the universe is dominated by matter when matter and antimatter are produced in equal amounts.

The Antiproton Decelerator (AD) at CERN acts as an antimatter factory, producing antiprotons whose fundamental properties can be measured. But the magnetic field induced within the AD prevents the necessary precision these measurements require.

To relocate the antiprotons to an environment suitable for experimentation, Smorra et al. developed a sort of package for the antimatter factory. Far from anything the postal system would provide, their transportable antiproton reservoir traps the particles with a magnetic field and confines them in a tight space with sides less than 100 micrometers long.

“We are measuring two fundamental properties of the antiproton: the charge-to-mass ratio and the magnetic moment,” said author Christian Smorra. “Both properties allow studying the fundamental interactions and their symmetries. If we find that protons and antiprotons have different absolute values, it would break one of the fundamental symmetries of the Standard Model of particle physics with dramatic consequences for the underlying theory.”

Once safely in the trap, the antiproton collides with electrons to cool down, and a superconducting tank-circuit dampens its motion. The trap is placed in an ultra-high vacuum cryogenic chamber with walls at 4.2 Kelvin to prevent annihilation with matter.

The team soon plans to showcase their capabilities at CERN, transporting first protons, then antiprotons.

“Transporting antimatter has been so far only science fiction, and it is very exciting to work on the technical developments to make this possible,” said Smorra.

Source: “BASE-STEP: A transportable antiproton reservoir for fundamental interaction studies,” by C. Smorra, F. Abbass, D. Schweitzer, M. A. Bohman, J. D. Devine, Y. Dutheil, A. Hobl, B. P. Arndt, B. B. Bauer, J. A. Devlin, S. R. Erlewein, M. Fleck, J. I. Jäger, B. M. Latacz, P. Micke, M. Schiffelholz, G. Umbrazunas, M. Wiesinger, C. Will, E. J. Wursten, H. Yildiz, K. Blaum, Y. Matsuda, A. Mooser, C. Ospelkaus, W. Quint, A. Soter, J. Walz, Y. Yamazaki, and S. Ulme, Review of Scientific Instruments (2023). The article can be accessed at https://doi.org/10.1063/5.0155492 .