Particle acceleration on the background of the Kerr-Taub-NUT spacetime

We study the collision of two particles with the different rest masses moving in the equatorial plane of a Kerr-Taub-NUT spacetime and get the center-of-mass (CM) energy for the particles. We find that the CM energy depends not only on the rotation parameter, a, but also on the NUT charge of the Kerr-Taub-NUT spacetime, n. Especially, for the extrema! Kerr-Taub-NUT spacetime, an unlimited CM energy can be approached if the parameter a is in the range [1, root 2], which is different from that of the Kerr and Kerr-Newman black holes. (C) 2011 Elsevier B.V. All rights reserved.