Proton transport from the antimatter factory of CERN.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40369070.
- Also identified by DOI 10.1038/s41586-025-08926-y and PMC identifier 12095035.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Precision measurements using low-energy antiprotons, exclusively available at the antimatter factory (AMF) of CERN<sup>1</sup>, offer stringent tests of charge-parity-time (CPT) invariance, which is a fundamental symmetry in the Standard Model of particle physics<sup>2</sup>. These tests have been realized, for example, in antiprotonic helium<sup>3</sup> and antihydrogen<sup>4</sup>. In our cryogenic Penning-trap experiments<sup>5</sup>, we measure the magnetic moments<sup>6,7</sup> and charge-to-mass ratios of protons and antiprotons and now provide the most precise test of CPT invariance in the baryon sector<sup>8</sup>. Our experiments are limited by magnetic field fluctuations imposed by the decelerators in the AMF; therefore, we are advancing the relocation of antiprotons to dedicated precision laboratories. Here we present the successful transport of a trapped proton cloud from the AMF using BASE-STEP<sup>9</sup>-a transportable, superconducting, autonomous and open Penning-trap system that can distribute antiprotons into other experiments. We transferred the trapped protons from our experimental area at the AMF onto a truck and transported them across the Meyrin site of CERN, demonstrating autonomous operation without external power for 4 h and loss-free proton relocation. We thereby confirm the feasibility of transferring particles into low-noise laboratories in the vicinity of the AMF and of using a power generator on the truck<sup>10</sup> to reach laboratories throughout Europe. This marks the potential start of a new era in precision antimatter research, enabling low-noise measurements of antiprotons, the charged antimatter ions <math xmlns="http://www.w3.org/1998/Math/MathML"> <msup> <mrow> <mover><mrow><mi>H</mi></mrow> <mo>¯</mo></mover> </mrow> <mrow><mo>+</mo></mrow> </msup> </math> <sup>11</sup> and <math xmlns="http://www.w3.org/1998/Math/MathML"> <msubsup> <mrow> <mover><mrow><mi>H</mi></mrow> <mo>¯</mo></mover> </mrow> <mrow><mn>2</mn></mrow> <mrow><mo>-</mo></mrow> </msubsup> </math> (ref. <sup>12</sup>), and other accelerator-produced ions, such as hydrogen-like lead or uranium ions<sup>13,14</sup>.