Studies of Exotic Physics with Antiprotons and Protons

About

S. Ulmer $^1$ , F. Abbass $^2$ , K. Blaum $^3$ , M. Bohman $^{1,3}$ , M. Borchert $^{1,4}$ , J. A. Devlin $^{1,5}$ , S. R. Erlewein $^{1,3,5}$, M. Fleck $^{1,6}$, J. I. Jaeger $^{1,3}$, B. M. Latacz $^{1}$, D. Popper $^2$, C. Smorra $^{1,2}$, G. Umbrazunas $^{1,7}$, M. Wiesinger $^{1,3}$, C. Will $^{3}$, E. J. Wursten $^{1,3}$, Y. Matsuda $^{6}$, C. Ospelkaus $^{4}$, W. Quint $^{7}$, A. Soter $^{8}$ , J. Walz $^{2}$ , Y. Yamazaki $^{1}$

$^{1}$ RIKEN, Ulmer Fundamental Symmetries Laboratory, Saitama, Japan; $^{2}$ Johannes Gutenberg-Universität, Mainz, Germany; $^{3}$ Max-Planck-Institut für Kernphysik, Heidelberg, Germany; $^{4}$ PTB, Braunschweig, Germany; $^{5}$ CERN, Geneva, Switzerland; $^{6}$ The University of Tokyo, Tokyo, Japan; $^{7}$ GSI - Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany; $^{8}$ ETH, Zuerich, Switzerland;

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 our universe, which inspires experiments to compare the fundamental properties of matter/antimatter conjugates with high precision. The BASE collaboration at the antiproton decelerator of CERN is performing such high-precision comparisons with protons and antiprotons. Using advanced cryogenic Penning traps, we have performed the most precise measurement of the proton-to-antiproton charge-to-mass ratio with a fractional uncertainty of 69 parts per trillion (p.p.t.) [1], which was recently improved by a factor of four to 16 p.p.t.[2]. In another measurement, we have invented a novel spectroscopy method, that allowed for the first direct measurement of the antiproton magnetic moment with a fractional precision of 1.5 parts in a billion [3]. Together with our last measurement of the proton magnetic moment [4] this improves the precision of previous magnetic moment based tests of the fundamental CPT invariance [5] by more than a factor of 3000. A…