Gauge invariant vortex vacuum textures and the gluon condensate

In SU(2) lattice gauge theory, a new self-restricted cooling procedure is developed which removes the SU(2)/Z2 coset fields from the lattice configurations and thus reveals the the Z2 vortex vacuum texture. The emerging gauge invariant vortex vacuum structure amounts to the full string tension. The action density of the vortex texture extrapolates to the continuum limit, and, hence, gives rise to a mass dimension four condensate which features in the operator product expansion and which is of pure vortex origin. keywords: center vortex, gauge invariance, gluon condensate, operator product expansion.