  We revisit the problem of plane monochromatic gravitational waves impinging
upon a Schwarzschild black hole using complex angular momentum techniques. By
extending our previous study concerning scalar and electromagnetic waves [A.
Folacci and M. Ould El Hadj, Phys.\, Rev.\, D {\bf 99}, 104079, (2019),
arXiv:1901.03965], we provide complex angular momentum representations and
Regge pole approximations of the helicity-preserving and helicity-reversing
scattering amplitudes and of the total differential scattering cross section.
We show, in particular, that for high frequencies (i.e., in the
short-wavelength regime), a small number of Regge poles permits us to describe
numerically with very good agreement the black hole glory and the orbiting
oscillations and we then provide a semiclassical approximation that unifies
these two phenomena.
