Grant: Special Research Opportunity Program - Project

ALPHA (Antihydrogen Laser PHysics Apparatus) is an international project just getting underway at CERN (European Centre for Particle Physics) in Geneva, whose aim is to achieve the first stable trapping of antihydrogen, the atomic form of neutral antimatter. We have put together an interdisciplinary team of Canadian scientists to help achieve this ambitious goal. Cold atoms of antihydrogen promise a unique opportunity to study the properties of atomic antimatter, and via comparisons with its well-studied matter-counterpart, the possibility to test if there are any differences between matter and antimatter. The symmetry between matter and antimatter, know as CPT symmetry, underpins our current understanding of the Universe. Violation of this symmetry, even a tiny amount, would shatter the theory of particle physics.   In 2002, the ATHENA experiment, and subsequently the ATRAP experiment, both located at CERN, succeeded in producing large quantities of cold antihydrogen atoms, achieving an important step in antimatter science. However the anti-atoms produced in these experiments, while nearly at rest, were not confined and soon annihilated on the walls of the apparatus. In order to probe matter-antimatter symmetry at the highest possible precision, it is essential that the anti-atoms be suspended in vacuum to allow for detailed interrogation, e.g. via laser light or microwaves. The primary objective of this initiative is to demonstrate, within the 3 years of the project duration, stable trapping of antihydrogen. If successful, it will open up an entirely new field of trapped atomic antimatter research, and may help provide a clue to a fundamental question of why our Universe is made of matter, but not antimatter.