Glossary

ALPHA. ALPHA is a research collaboration and project created to investigate the characteristics of antimatter in the form of antihydrogen. It was created in 2005 at CERN as a continuation of the research carried out by the ATHENA Project. Many of the members of ATHENA are now working in ALPHA as well. The goals of the project are to produce and trap atoms of antihydrogen to carry out a spectroscopic comparison between them and hydrogen atoms in order to test various physical properties such as CPT symmetry and the effect of gravity on the antiparticles. Click here for more details or visit the official science webpage of ALPHA at http://alpha.web.cern.ch/alpha/

AMS (Alpha Magnetic Spectrometer). The AMS is a high energy particle detector that will try to detect the presence of very small amounts of antimatter, while orbiting at an altitude of a few hundred kilometers above the atmosphere. The collaboration unites physicists from all over the words, lead by Nobel prize laureate Prof. Samuel Ting of MIT. Read more about the AMS Project at http://cyclo.mit.edu/~bmonreal/ and http://livefromcern.web.cern.ch/livefromcern/antimatter/history/AM-history03-a.html

Annihilation. Annihilation is the process that matter and antimatter undergo when they meet, which consists of a sudden transformation of their masses into energy (into photons).

Antideuterium. Antideuterium is the antimatter counterpart of deuterium. Deuterium is an atomic nucleus composed of one proton and one neutron. Antideuterium, therefore, is made of an antiproton and an antineutron.

Antielectron. The antielectron is the antimatter counterparticle of the electron. It has the same mass and the same properties as the electron, except for its electrical charge, which has the opposite sign. The antielectron is charged positively, hence it is also called "positron". Antielectrons can combine with other antiparticles to create atoms of antimatter.

Antihydrogen. Antihydrogen is the antimatter counterpart of hydrogen. The atom of antihydrogen is made of one antiproton and one antielectron or positron. It is stable as the hydrogen atom, but because it is antimatter in a world made of matter, it very soon annihilates and disappears.

Antimatter. Antimatter is "another form of matter", with all the characteristics of matter, expect for the electrical charge, which has the opposite sign. What is positively charged in matter is negatively charged in antimatter, and vice versa. Our universe is made of matter, but it is argued that right after the Big Bang both matter and antimatter were created. Antimatter disappeared through annihilation, but some matter remained and formed the universe we inhabit today. Nowadays, antimatter can only be observed in the world as a byproduct of certain high energy physical reactions and it is extremely short lived. For more details on antimatter, its discovery and uses click here.

Antineutron. The antineutron is the antimatter counterparticle of the neutron. It has all the features of the latter, except for the electrical charge of its constituent parts, the quarks, which is opposite to that of the quarks in the neutron. As any other antiparticle, it behaves like matter and can associate with other antiparticles, such as the positron and the antiproton, to form stable atoms.

Antiparticle. A fundamentally stable quantity of antimatter. Some examples of antimatter are the antielectrons (also called positrons), antineutrons and antiprotons.

Antiproton. The antineutron is the antimatter counterparticle of the neutron. It has all the features of the latter, except for its electrical charge, which has the opposite sign. While protons have positive charges, antiprotons have negative ones. Like any other antiparticle, it behaves like matter and can associate with other antiparticles, as the positron, to form stable atoms.

Antiproton Decelerator (AD). A large machine at CERN which accomplishes the special goal of slowing high-energy antiprotons produced by one of CERN’s particle accelerators for use by experiments that require slow or ‘cold’ antiprotons. Read more about the utilities of the AD at: http://cern.web.cern.ch/livefromcern/antimatter/factory/AM-factory01.html

ATHENA. ATHENA was an international collaboration and project started in 1996 at CERN to produce antimatter atoms in quantities larger than were available to the date. In 2002 they achieved their goal, being the first to produce tens of thousands of cold antihydrogen atoms. Learn more about their research, members and achievements at their official science webpage: http://athena.web.cern.ch/athena/

ATRAP. ATRAP is one of the first collaborations working towards antihydrogen production and trapping. Read more about their work at: http://hussle.harvard.edu/~atrap/

Big Bang. The Big Bang is the explosion that, according to modern Physics, caused the beginning of our universe. Before the Big Bang there was no matter, but simply enormous amounts of energy extremely condensed in just one point. An explosion took place that generated the appearance of matter and antimatter and their expansion, or movement away from the location of the Big Bang.

CERN. CERN is the Organisation Européenne pour la Recherche Nucléaire (European Organization for Nuclear Research). The acronym CERN comes from its former name: Conseil Européen pour la Recherche Nucléaire (European Council for Nuclear Research). The center is near Geneva (Switzerland), on the French border. Read more about the organization and its projects at: http://public.web.cern.ch/Public/Welcome.html

Cold antihydrogen. Antihydrogen atoms with very little kinetic energy.

Cosmic rays. Energetic particles which enter the Earth’s atmosphere from space. There are many sources of cosmic rays ranging from stars like our Sun to far away galaxies.

E = mc². Famous equation entailed by Einstein’s Theory of Relativity. This equation describes the fundamental relationship between mass (m) and energy (E), and means that Energy (E) is the product of mass (M) times the speed of light squared (c²).

Electron-volt (eV). The amount of energy gained by an electron that is accelerated across a potential of 1 electrical volt. (One electrical volt is approximately the voltage provided by a single AA battery.)

Fermilab. The Fermilab laboratory in Chicago was one of the first to produce antimatter atoms and it has the largest particle accelerator currently working in the world. Its name is Tevatron, and it is capable of accelerating particles to energies of 1.8 TeV (1800 GeV). The latest version of CERN's Large Hadron Collider is larger than the Tevatron, but it is not running yet. Visit Fermilab's official webpage at http://www.fnal.gov/

Gamma rays. A term for high-energy x-rays.

Gigaelectrons-volt (GeV). 1 billion (10⁹) electron volts (eV).

Large Hadron Collider. The largest particle accelerator in the world. Currently under construction at CERN. For more information about its characteristics, construction and uses, see: http://lhc.web.cern.ch/lhc/

Low Energy Antiproton Ring (LEAR). A special machine at CERN which in the past was used to store low-energy antiprotons produced by particle accelerators for use in experiments which needed beams of antiprotons. This device was also used in early antiproton experiments to demonstrate the feasibility of techniques which would ultimately be used in conjunction with the Antiproton Decelerator (AD) to trap cold antiprotons for use in antihydrogen production. This machine was decommissioned and has been ‘replaced’ by the AD. You can read more about its functioning and use at : http://livefromcern.web.cern.ch/livefromcern/antimatter/history/AM-history02-c.html and http://livefromcern.web.cern.ch/livefromcern/antimatter/history/AM-history01-d.html

Octupole magnet. A special magnet that produces a magnetic field that is equivalent to the field produced by a particular arrangement of 8 bar magnets (poles).

Photon. A photon is defined as a single particle of light.

Positron. Positron is the common name for the "antielectron". The positron is the antimatter counterparticle of the electron. It has the same mass and the same properties as the electron, except for its electrical charge, which has the opposite sign. The positron is charged positively, hence its name, derived from the terms "positive" and "electron". Positrons can combine with other antiparticles to create atoms of antimatter.

Quarks. Quarks are one of the two types of fundamental particles into which matter can be divided. Their antimatter counterparts are called "antiquarks". Large particles such as protons and neutrons are made of quarks.

Quantum Theory. A fundamental theory in Physics which describes processes that are governed by wavefunctions. It receives a reputation for being strange owing to the fact that physically observable quantities are fundamentally probabilities rather than certainties.

Theory of Relativity. The theory developed by Albert Einstein that states that all physical laws operate the same in every place in the universe and in every frame of reference. This theory correctly predicts strange behavior such as time and space dilation for beings moving relatively to each other at high rates of speed. It also predicts that nothing can go faster than the speed of light.