title: Sixfold improved single particle measurement of the magnetic moment of the antiproton.
abstract: Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nagahama
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|CERN, CH-1211 Geneva 23, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Smorra
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sellner
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Harrington
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Higuchi
authors.affiliation: Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Borchert
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Besirli
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Mooser
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Schneider
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Blaum
authors.affiliation: Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: Y
authors.identifier: 0000-0002-9847-3791
authors.initials: Y
authors.lastname: Matsuda
authors.affiliation: Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany.|Physikalisch-Technische Bundesanstalt, QUEST, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: C
authors.identifier: 0000-0002-4170-2936
authors.initials: C
authors.lastname: Ospelkaus
authors.affiliation: GSI-Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Quint
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz, Germany.|Helmholtz-Institut Mainz, sektion MAM, 55099 Mainz, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Walz
authors.affiliation: RIKEN, Atomic Physics Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamazaki
authors.affiliation: RIKEN, Ulmer Initiative Research Unit, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: S
authors.identifier: 0000-0002-4185-4147
authors.initials: S
authors.lastname: Ulmer