Solitonic d−5 brane and vortex defects on the world-sheet

We examine the behavior of the vortex defects on the world-sheet when a solitonic d−5 brane is existing in the d-dimensional target space, and it is seen that the vortices of any charge should be dissociated to the free-gas phase when they approach to the brane. The meanings of this fact are addressed through the analysis of the renormalization group equations on the world sheet.