Gauge invariant Z ( 2 ) vortex vacuum textures and the SU ( 2 ) gluon condensate

For SU(2) lattice gauge theory, a new SO(3) cooling procedure is proposed which removes the SU(2)/Z(2) coset fields from the lattice configurations and reveals a Z(2) vortex vacuum texture different from the P–vortex content obtained in the maximal center gauge. Cooling can be restricted in a renormalization group invariant way by a parameter controlling the remaining SO(3) action density. A gauge invariant Z(2) vortex vacuum emerges asymptotically if cooling is not restricted. This “vortex texture” does not support the string tension σ or a finite part of it. The SU(2) action density associated with the new Z(2) vortex texture has a smooth extrapolation to the continuum limit. We propose an interpretation as a mass dimension four condensate related to the gluon condensate featuring in the operator product expansion. PACS: 11.15.Ha 14.70.Dj keywords: center vortex, gauge invariance, confinement, gluon condensate, operator product expansion.