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:
“People believe a man is in distress because his loved one dies in one day. But his real pain is less futile: it is that he finds out that sadness too does not last. Even pain has no meaning.”
—Albert Camus (1913–1960)
“I feel the carousel starting slowly
And going faster and faster: desk, papers, books,
Photographs of friends, the window and the trees
Merging in one neutral band that surrounds
Me on all sides, everywhere I look.”
—John Ashbery (b. 1927)
“Love is life. All, everything that I understand, I understand only because I love. Everything is, everything exists, only because I love. Everything is united by it alone. Love is God, and to die means that I, a particle of love, shall return to the general and eternal source.”
—Leo Tolstoy (1828–1910)