THE INTERACTION OF SKYRME-LIKE LUMPS IN (2+1) DIMENSIONS

A model is considered in (2 + 1) spacetime dimensions in which Skyrme-like lump solutions exist. A static lump resembles the instanton solution of the O(3) sigma model but has a fixed size. Using a collective coordinate method the interaction between two lumps is studied. It is shown that a repulsive force exists between lumps which also distorts their size during close range interactions. For initial velocities below a critical value the lumps scatter back-to-back whereas for larger velocities the scattering is at right angles to the initial direction of motion in the centre of mass frame.