  It has been recently suggested that when an Anderson impurity is immersed in
the bulk of a topological insulator, a Kondo resonant peak will appear
simultaneously with an in-gap bound-state when the band-dispersion has an
"inverted-Mexican-hat" form. The mid-gap bound-state generates another spin
state and the Kondo effect is thereby screened. In this paper we study this
problem within a weak-coupling RG scheme where we show that the system exhibits
complex crossover behavior between different symmetry configurations and may
evolve into a self-screened-Kondo or SO(3) low energy fix point. Experimental
consequences of this scenario are pointed out.
