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.
== See also ==
BPST instanton
dyon
instanton
monopole
