Observation of the 1S-2S transition in trapped antihydrogen
Authors: The ALPHA Collaboration including, William Bertsche, Mark Johnson
Publication Date: 26 January, 2017
Department of: Physics and Astronomy
Antimatter is one of the grandest conundrums facing physics. It’s predicted existence by Paul Dirac in 1928 and experimental confirmation shortly thereafter marks one of the greatest achievements in theoretical physics in the last century. However, the apparent scarcity of this substance in the universe in opposition to prediction remains one of the deepest mysteries facing current theories. A frenzy of activity today both in the realm of theory and experiment aims to address this discrepancy. The ALPHA experiment at CERN has recently reported a first-of-its-kind measurement in the effort to understand this apparent baryon asymmetry. The team at CERN, including members from the University of Manchester, trapped antihydrogen atoms and used a laser to drive these anti-atoms from their ground state to first atomic excited state. This result is an important milestone in performing precision optical spectroscopy of anti-atoms in order to test the hypothesis that atomic spectra should be exactly the same between an atom and its antimatter twin – as it stands it provides a one-sided test of antimatter-matter symmetry at the 1 part in 1010 level.
- Antihydrogen: the antimatter version of a hydrogen atom consisting of a positron and antiproton
- Accelerators at CERN are required to create the antiprotons used in this experiment.
- Positrons in this work are acquired from specially-produced radioactive table salt.
- This is the first observation of an optical transition in any antimatter system.