Sphaleron of a 4 dimensional SO(4) Higgs model

We construct the finite energy path between topologically distinct vacua of a 4 dimensional SO(4) Higgs model which is known to support an instanton, and show that there is a sphaleron with Chern–Simons number NCS=12 at the top of the energy barrier. This is carried out using the original geometric loop construction of Manton.