Center vortex model for the infrared sector of Yang–Mills theory — topological susceptibility Original Research Article

A definition of the Pontryagin index for SU(2) center vortex world-surfaces composed of plaquettes on a hypercubic lattice is constructed. It is used to evaluate the topological susceptibility in a previously defined random surface model for vortices, the parameters of which have been fixed such as to reproduce the confinement properties of SU(2) Yang–Mills theory. A prediction for the topological susceptibility is obtained which is compatible with measurements of this quantity in lattice Yang–Mills theory.