  We deliver the realistic ab initio lattice investigations of $K \overline{K}$
scattering. In the Asqtad-improved staggered dynamical fermion formulation, we
carefully measure $K\overline{K}$ four-point function in the $I=0$ channel by
moving wall sources without gauge fixing, and clearly find an attractive
interaction in this channel, which is in agreement with the theoretical
predictions. An essential ingredient in our lattice calculation is to properly
treat the disconnected diagram. Moreover, we explain the difficulties of these
lattice calculations, and discuss the way to improve the statistics. Our
lattice investigations are carried out with the MILC $2+1$ gauge configuration
at lattice spacing $a \approx 0.15$~fm.

High Energy Physics - Lattice