Particles Not Formed of Quarks
Particles without any quarks have a baryon number of zero. Such particles include leptons (electron, muon, tau and their neutrinos) and gauge bosons (photon, W and Z bosons and gluons); or the hypothetical graviton.
Read more about this topic: Baryon Number
Famous quotes containing the words particles and/or formed:
“The atoms of Democritus
And Newton’s particles of light
Are sands upon the Red Sea shore,
Where Israel’s tents do shine so bright.”
—William Blake (1757–1827)
“The shifting islands! who would not be willing that his house should be undermined by such a foe! The inhabitant of an island can tell what currents formed the land which he cultivates; and his earth is still being created or destroyed. There before his door, perchance, still empties the stream which brought down the material of his farm ages before, and is still bringing it down or washing it away,—the graceful, gentle robber!”
—Henry David Thoreau (1817–1862)