Annihilation of nematic point defects: postcollision scenarios.

We perform a study of the annihilation of a nematic radial and hyperbolic point defects with the main focus on the confinement induced collision and postcollision scenarios. Brownian molecular dynamics on a semimicroscopic lattice is used. Initially a pair of defects, separated for 1.4-1.7 radii, is induced at the axis of the cylindrical capillary. In such a configuration defects start to approach slowly. In the early stage, their cores are negligibly influenced by the mutual interaction. When the distance becomes comparable to the nematic correlation length, the cores significantly deform. In the collision regime, defects gradually merge. We observe two qualitatively different scenarios in the postcollision regime, depending on the degree of (meta) stability of the initially imposed escaped structure with point defects.