Arman TursunovM. Kološ; A. Abdujabbarov; B. Ahmedov; Z. Stuchlík45 min

High Energy Collision of Particles in Black String Spacetimes

It has been shown by Bañados, Silk and West (BSW) that a rotating axially symmetric black hole can act as a particle accelerator to arbitrarily high energies in the center-of-mass frame of the collision of a pair of particles. In particular, the BSW effect takes place when particles have the properly chosen values of angular momentum. In this talk I will present several similar mechanisms of particle acceleration in the spacetimes with extended horizon topology, namely, the spacetime of the five-dimensional black string. We consider three different cases of the center-of-mass collisions of particles: a) collision of neutral particles in static black string spacetime, b) collision of charged particles in external magnetic field, and c) collision of neutral particles in the spacetime of rotating black string. We will see, that the unlimited center-of-mass energy can be approached in the case of the extremal rotation of the black string which is similar to the analogous effect in Kerr spacetime. However in the black string spacetime the scattering energy of particles in the center-of-mass system can take arbitrarily large values also for non-extremal spacetimes. In the presence of external magnetic field the collision of two same charged particles revolving at the same ISCO in the opposite directions does not give the result of the high energy. However this energy can be large for the collision of a particle falling from infinity with a charged particle moving at ISCO. Moreover, the collision energy formally infinitely grows for ISCO arbitrary close to the horizon, which strongly depends on the values of external magnetic field, the angular momentum of a particle and black string properties.