Rotating 4D Gauss–Bonnet black hole as a particle accelerator

Abstract

We demonstrate that the rotating four-dimensional Gauss– Bonnet black hole can act as a particle accelerator with arbitrarily high centre-of-mass (CM) energy, when collision of two general particles takes place near the event horizon. The particles are at rest initially at infinity, and by fine tuning their angular momenta within a finite range, they are released so that they follow the time-like geodesics in the black hole spacetime, and the collision taking place on the equatorial plane is observed. The Gauss–Bonnet coupling constant α, provides a deviation in the results, from that observed in the Kerr black hole. The horizon structure, the range of allowed angular momentum and the critical angular momentum depend on the value of α. Our results show that the CM energy depends on the coupling parameter α in addition to the black hole spin a. For extremal cases, the CM energy diverges at the horizon, suggesting that Gauss–Bonnet black hole can also act as a particle accelerator similar to a Kerr black hole. For the non-extremal case, there exists a finite upper bound on the CM energy, the maximal value of which depends on the parameter α.