Maximal efficiency of the collisional Penrose process with spinning particles in Kerr-Sen black hole

Understand

We study the collision of two uncharged spinning particles around an extreme Kerr-Sen black hole and calculate the maximal efficiency of the energy extraction from the Kerr-Sen black hole via super Penrose process.

• We consider the collision of two massive particles as well as collision of a massless particle with a massive particle.
• For all the cases, we find that the maximum efficiency decreases as the Kerr-Sen black hole's parameter($b=1-a$) increases.