Planckian Scattering From Kerr Black Holes: Eikonal and Beyond
  Planckian scattering of particles with angular momenta is studied by describing them as sources of Kerr metric. In the shock wave formalism, it is found that the angular momenta do not contribute to the scattering amplitude in the eikonal limit. This is confirmed by using the wave equation of the test particle in the Kerr background. 
Saurya Das and R. Parthasarathy