  Lattice gauge theory results show the confinement for the quark potential in
different Yang-Mills theories and even the G(2) gauge theory. LGT calculations
show that quark potential should have the down concavity behavior. Confinement
properties can be explained using the thick center vortex model. However an
upward concavity is seen in the quark potential intervals using this model.
After study the reason of this concavity, it is shown the non physical
concavity can be reduced by taking an arbitrary symmetric vortex flux in the
space time plane of the lattice.
