Meron (physics)

A meron or half-instanton is a Euclidean space-time solution of the Yang-Mills field equations. It is a singular non-self-dual solution of topological charge 1/2. The instanton is believed to be composed of two merons.

A meron can be viewed as a tunneling event between two Gribov vacua. In that picture, the meron is an event which starts from vacuum, then a Wu-Yang monopole emerges, which then disappears again to leave the vacuum in another Gribov copy.