In particle physics, a real neutral particle is an elementary particle that is its own antiparticle. Known examples include photons, Z bosons, and neutral pions; along with the hypothetical Higgs bosons, neutralinos, sterile neutrinos, and gravitons (if they exist).
The electromagnetic charge, weak charge, and strong charge of such a particle must be the same as that of its antiparticle. In the case of the electric and strong charges, this implies that the charge must be zero.
For a spin-1/2 particle such as the (hypothetical) neutralino, being a real neutral particle means being a Majorana fermion.
Famous quotes containing the words real, neutral and/or particle:
“We are tainted by modern philosophy which has taught us that all is good, whereas evil has polluted everything and in a very real sense all is evil, since nothing is in its proper place.”
—Joseph De Maistre (1753–1821)
“The seashore is a sort of neutral ground, a most advantageous point from which to contemplate this world. It is even a trivial place. The waves forever rolling to the land are too far-traveled and untamable to be familiar. Creeping along the endless beach amid the sun-squall and the foam, it occurs to us that we, too, are the product of sea-slime.”
—Henry David Thoreau (1817–1862)
“The way to learn German, is, to read the same dozen pages over and over a hundred times, till you know every word and particle in them, and can pronounce and repeat them by heart.”
—Ralph Waldo Emerson (1803–1882)