`Blowing up' D-branes on Non-supersymmetric Cycles

Abstract

In the orbifold limit of K3, one can give exact conformal field theory description of D-branes wrapped on certain non-supersymmetric cycles of K3. We study the effect of switching on the `non-geometric blow up modes' corresponding to anti-symmetric tensor gauge field flux through the 2-cycles on these D-branes. Working to first order in the blow up parameter, we determine the region of the moduli space in which these D-branes are stable. Across the boundary of this region, the D-brane wrapped on the non-supersymmetric cycle decays to a pair of D-branes, each wrapped on a supersymmetric cycle, via a second order phase transition.