It is shown that static purely electric or purely magnetic Abelian field configurations in Yang-Mills theory are unstable when the electric or magnetic field strength is too large over too wide a region. The critical parameter is $\mathrm{gE}{L}^2$ ($\mathrm{gB}{L}^2$), where $E \mathrm{}\left(B\right)\mathrm{}$ is a measure of the field strength and $L$ is a measure of the distance over which such field strengths extend.

• Received 27 March 1979

DOI:https://doi.org/10.1103/PhysRevD.20.877