  We discuss effective interactions among brane matter induced by modifications
of higher dimensional Einstein gravity through the replacement of
Einstein-Hilbert term with a generic function f(R, R_AB R^AB, R_ABCD R^ABCD) of
the curvature tensors. We determine gravi-particle spectrum of the theory, and
perform a comparative analysis of its predictions with those of the Einstein
gravity within Arkani-Hamed--Dvali--Dimopoulos (ADD) setup. We find that this
general higher-curvature quantum gravity theory contributes to scatterings
among both massive and massless brane matter (in contrast to much simpler
generalization of the Einstein gravity, f(R), which influences only the massive
matter), and therefore, can be probed via various scattering processes at
present and future colliders and directly confronted with the ADD expectations.
In addition to collision processes which proceed with tree-level gravi-particle
exchange, effective interactions among brane matter are found to exhibit a
strong sensitivity to higher-curvature gravity via the gravi-particle loops.
Furthermore, particle collisions with missing energy in their final states are
found to be sensitive to additional gravi-particles not found in Einstein
gravity. In general, road to a correct description of quantum gravity above
Fermi energies depends crucially on if collider and other search methods end up
with a negative or positive answer for the presence of higher-curvature
gravitational interactions.
