from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A subatomic particle, such as a positron, antiproton, or antineutron, having the same mass, average lifetime, spin, magnitude of magnetic moment, and magnitude of electric charge as the particle to which it corresponds but having the opposite sign of electric charge, opposite intrinsic parity, and opposite direction of magnetic moment. See Table at subatomic particle.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A subatomic particle corresponding to another particle with the same mass, spin and mean lifetime but with charge, parity, strangeness and other quantum numbers flipped in sign.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a particle that has the same mass as another particle but has opposite values for its other properties; interaction of a particle and its antiparticle results in annihilation and the production of radiant energy
Sorry, no etymologies found.
With similar methods an antiparticle to the neutron has subsequently been discovered, a discovery whose importance lies in the fact that the concept of the antiparticle was thereby extended to include also the neutral elementary particles.
And I’m no fan of the MP for Ladywood – though for years I considered her a kind of antiparticle Ann Widdicombe, whose honesty you can applaud even while disagreeing with her.
The history of antimatter begins with the physicist Paul Dirac whose work in the late 1920s established the fact that for every particle there is a corresponding antiparticle, exactly matching the particle but with opposite charge.
This is the force responsible for nuclear beta decay, which, for example, permits a neutron to decay into a proton, electron, and a third particle -- the neutrino which without extremely carefully designed experiments leaves no observable signatures of its own strictly speaking, it is the neutrino's antiparticle known as the antineutrino.
The neutrino has almost no mass, comes in three different "flavors," may have its own antiparticle and has been seen shifting from one flavor to another while shooting out from our sun, said physicist Phillip Schewe, communications director at the Joint Quantum Institute in Maryland.
This process differs from what is expected for the bottom quark's antiparticle, the anti-bottom quark, and thus the symmetry is broken.
Nevertheless, it was thought that mirror symmetry would indeed apply to all particle reactions if it were combined with the operation of changing a particle to its antiparticle.
The answer is that, in quantum theory, particles can be created out of energy in the form of particle/antiparticle parts.
A particle can jump backward in time, in which case it looks like its antiparticle.
The common view was that when a particle met its antiparticle, the pair destroyed each other in an explosion.