| ELENA | Extra low energy antiproton ring – further decelerates antiprotons coming from AD |
|---|---|
| AD experiments | |
| ATHENA | AD-1 Antihydrogen production and precision experiments |
| ATRAP | AD-2 Cold antihydrogen for precise laser spectroscopy |
| ASACUSA | AD-3 Atomic spectroscopy and collisions with antiprotons |
| ACE | AD-4 Antiproton cell experiment |
| ALPHA | AD-5 Antihydrogen laser physics apparatus |
| AEgIS | AD-6 Antihydrogen experiment gravity interferometry spectroscopy |
| GBAR | AD-7 Gravitational behaviour of anti-hydrogen at rest |
| BASE | AD-8 Baryon antibaryon symmetry experiment |
| PUMA | AD-9 Antiproton unstable matter annihilation |
The Antihydrogen Laser Physics Apparatus (ALPHA), also known as AD-5, is an experiment at CERN's Antiproton Decelerator, designed to trap antihydrogen in a magnetic trap in order to study its atomic spectra. The ultimate goal of the experiment is to test CPT symmetry through comparing the respective spectra of hydrogen and antihydrogen.[1] Scientists taking part in ALPHA include former members of the ATHENA experiment (AD-1), the first to produce cold antihydrogen in 2002.
On 27 September 2023, ALPHA collaborators published findings suggesting that antimatter interacts with gravity in a way similar to regular matter, supporting a prediction of the weak equivalence principle.[2][3]
- ^ Madsen, N. (2010). "Cold antihydrogen: a new frontier in fundamental physics". Philosophical Transactions of the Royal Society A. 368 (1924): 3671–82. Bibcode:2010RSPTA.368.3671M. doi:10.1098/rsta.2010.0026. PMID 20603376. S2CID 12748830. Archived from the original on 2020-03-29. Retrieved 2021-07-22.
- ^ Overbye, Dennis (27 September 2023). "Nothing's the Matter With Antimatter, New Experiment Confirms - Consider it good news, physicists say: "The opposite result would have had big implications."". The New York Times. Archived from the original on 27 September 2023. Retrieved 28 September 2023.
- ^ Anderson, E. K. (27 September 2023). "Observation of the effect of gravity on the motion of antimatter". Nature. 621 (7980): 716–722. Bibcode:2023Natur.621..716A. doi:10.1038/s41586-023-06527-1. hdl:20.500.11850/636368. PMC 10533407. PMID 37758891.