  Modeling glueballs as bound states of transverse constituent gluons allows to
understand the main features of the lattice QCD glueball spectrum. In
particular it has been shown in previous works that the lightest C-even
glueballs can be seen as bound states of two transverse constituent gluons
interacting via a funnel potential. In the present study we show that such an
effective potential emerges from the available lattice QCD data. Starting from
the scalar glueball mass and wave function computed in lattice QCD, we indeed
compute the equivalent local potential between two transverse constituent
gluons in the scalar channel and show that it is compatible with a funnel
shape, where standard values of the parameters are used and where a negative
constant has to be added to reproduce the absolute height of the potential.
Such a constant could be related to instanton-induced effects in glueballs.
