  The color fields in a system composed by two static quarks and two static
antiquarks are studied. In particular, we consider the four particles in the
corners of a rectangle, and two possible alignment of the particles, one in
which the quarks are at the same side of the rectangle, and the other where
they are at opposite sides. We use a variational method, to probe not only the
ground state but also the first excited state. This results permit us to
observe and interpret the flux-tube recombination in the mesons to mesons and
the tetraquark to mesons transitions, for both states. The results are compared
with previous results for the static potential and the Casimir scaling
predictions.
