  Using SU(3) quenched lattice QCD, we study ground-state and low-lying
even-parity excited-state potentials of quark-antiquark systems in terms of the
gluon-momentum component in the Coulomb gauge. By introducing UV-cut in the
gluon-momentum space, we investigate the "UV-gluon sensitivity" of the
ground-state and excited-state potentials and the stringy excitation
quantitatively. Even after cutting off high-momentum gluon component above
1.5GeV, the IR part of the ground-state potential is almost unchanged. On the
other hand, the change of excited-state potential is more significant by the
cut of UV-gluons. However, even after the removal of UV-gluons, the magnitude
of the low-lying gluonic excitation remains to be of the order of 1GeV.
