  In color SU(2) lattice QCD, we investigate colored-diquark distributions in
two-hadron scatterings by means of Bethe-Salpeter amplitudes on the lattice.
With colored-diquark operators in the Coulomb gauge, we measure components of
two colored diquarks realized as intermediate states via one gluon exchange
(OGE) processes in hadron scattering. From the colored-diquark distributions,
we estimate the dominant range of gluon (color) exchanges between closely
located two hadrons. We find that the colored-diquark components are enhanced
at the short range ($\leq$0.2 fm) and their tails show the single-exponential
damping. In order to distinguish the genuine colored-diquark components
originating in the color exchange processes from trivial colored two-quark
components contained in two color-singlet hadrons as a result of simple
transformation of hadronic basis, we repeat the analyses on the artificially
constructed gauge fields, where low- and high-momentum gluon components are
decoupled and only restricted pair of quarks can share and exchange
low-momentum gluons. We observe qualitatively the same behaviors and confirm
that the short-range enhancement of the colored-diquark distributions is the
genuine OGE-origin color excitation in hadron scattering.
