0000000001003373
AUTHOR
J. A. Harrington
A 16-parts-per-trillion measurement of the antiproton-to-proton charge–mass ratio
The standard model of particle physics is both incredibly successful and glaringly incomplete. Among the questions left open is the striking imbalance of matter and antimatter in the observable universe, which inspires experiments to compare the fundamental properties of matter/antimatter conjugates with high precision. Our experiments deal with direct investigations of the fundamental properties of protons and antiprotons, performing spectroscopy in advanced cryogenic Penning trap systems. For instance, we previously compared the proton/antiproton magnetic moments with 1.5 parts per billion fractional precision, which improved upon previous best measurements by a factor of greater than 3,0…
Testing CPT Invariance by High-Precision Comparisons of Fundamental Properties of Protons and Antiprotons at BASE
The BASE collaboration at the Antiproton Decelerator facility of CERN compares the fundamental properties of protons and antiprotons using advanced Penning-trap systems. In previous measurement campaigns, we measured the magnetic moments of the proton and the antiproton, reaching (sub-)parts-in-a-billion fractional uncertainty. In the latest campaign, we have compared the proton and antiproton charge-to-mass ratios with a fractional uncertainty of 16 parts in a trillion. In this contribution, we give an overview of the measurement campaign, and detail how its results are used to constrain nine spin-independent coefficients of the Standard-Model Extension in the proton and electron sector.