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[en] High-precision comparisons of the proton-to-antiproton charge-to-mass ratios provide sensitive tests of the fundamental charge, parity, time (CPT) invariance. In 2014, we performed such a measurement with a fractional precision of 69parts in a trillion (p.p.t.). In this article, we describe technical developments which were implemented to improve the precision of our previous measurement by at least a factor of 3.
[en] We summarize our recent 1.5 parts per billion measurement of the antiproton magnetic moment using the multi Penning-trap system of the BASE collaboration. The result was achieved by combining the detection of individual spin-transitions of a single antiproton with a novel two-particle spectroscopy technique, which dramatically improved the data sampling rate. This measurement contributes to improve the test of the fundamental charge, parity, time reversal (CPT) invariance in the baryon sector by a factor of 350 compared to our last measurement, and by a factor of 3000 compared to the best competing measurement. We review the measurement technique and discuss the improved limits on CPT-violating physics imposed by this measurement.
[en] Elementary examples are provided of reaction rate matrices satisfying the constraints of unitarity and CPT invariance, which can lead a system with baryon number initially zero to evolve toward non-zero baryon number. The importance of the unitarity constraint is emphasized. (Auth.)
[en] The issue of testing CPT invariance in neutral-meson systems is considered. Possible experiments in both fixed-target and factory situations are studied. We construct rate asymmetries that can be used to extract various CPT-violating parameters from these experiments. Estimates are given of the bounds on CPT violation that could be generated in present and planned machines
[en] The ATHENA experiment at the Antiproton Decelerator facility at CERN aims at testing CPT symmetry with antihydrogen. An overview of the experiment, together with preliminary results of development towards the production of slow antihydrogen are reported.
[en] It is commonly believed that unbroken supersymmetry (SUSY) implies that all members of a supermultiplet have the same mass. We demonstrate that this is not true, by exhibiting a simple counterexample. We employ the formalism of homeotic fermions, in a simple model where CPT conjugate fermions have different masses. This model can be supersymmetrized to a hypermultiplet of fields which form a representation of the conventional N=2 SUSY algebra. Nevertheless, CPT conjugate states in this hypermultiplet have different masses. These surprising results do not violate either the CPT theorem or the Haag-Lopuszanski-Sohnius theorem
[en] The MINOS Far Detector is a 5400 ton iron calorimeter located at the Soudan state park in Soudan Minnesota. The MINOS far detector can observe atmospheric neutrinos and separate charge current νμ and (bar ν)μ interactions by using a 1.4 T magnetic field to identify the charge of the produced muon. The CPT theorem requires that neutrinos and anti-neutrinos oscillate in the same way. In a fiducial exposure of 5.0 kilo-ton years a total of 41 candidate neutrino events are observed with an expectation of 53.1 ± 7.6(system.) ± 7.2(stat.) unoscillated events or 31.6 ± 4.7(system.) ± 5.6(stat.) events with Δm2 = 2.4 x 10-3 eV2, sin2(2θ) = 1.0 as oscillation parameters. These include 28 events which can have there charge identified with high confidence. These 28 events consist of 18 events consistent with being produced by νμ and 10 events being consistent with being produced by (bar ν)μ. No evidence of CPT violation is observed