Motion of a particle with isospin in the presence of a monopole

From a consistent expression for the quadriforce describing the interaction between a colored particle and gauge fields, we investigate the relativistic motion of a particle with isospin interacting with a BPS monopole and with a Julia-Zee dyon. The analysis of such systems reveals the existence of unidimensional unbounded motion and asymptotic trajectories restricted to conical surfaces, which resembles the equivalent case of electromagnetism.