  Here we consider static, axially symmetric, rotating and charged Kerr-Sen
Dilaton-Axion black hole metric in generalized Boyer-Lindquist coordinates as
particle accelerators. We obtain the geodesic motions of particle. We find the
effective potential and discuss the circular orbit of a particle. We
investigate the center of mass energy of two colliding neutral particles with
different rest masses falling from rest at infinity to near the non-extremal
horizons (event horizon and Cauchy horizon) and extremal horizon of the
Kerr-Sen black hole. Analogous to the Compton process, we discuss the collision
of a particle and a massless photon. Finally, we find the center of mass energy
due to the collision of two photons in the background of Kerr-Sen black hole.

General Relativity and Quantum Cosmology