2 An Exotic Particle Model with a Coulomb and a Magnetic Vortex Interaction

We consider the Lagrangian particle model introduced in [1] for zero mass but nonvanishing second central charge of the planar Galilei group. Extended by a magnetic vortex or a Coulomb potential the model exibits conformal symmetry. In the former case we observe an additional SO(2, 1) hidden symmetry. By either a canonical transformation with constraints or by freezing scale and special conformal transformations at t = 0 we reduce the six-dimensional phase-space to the physically required four dimensions. Then we discuss bound states (bounded solutions) in quantum dynamics (classical mechanics). We show that the Schrödinger equation for the pure vortex case may be transformed into the Morse potential problem thus providing us with an explanation of the hidden SO(2, 1) symmetry.