Stable non-BPS states on a 3-brane probe

As a novel application of string junctions, we construct stable non-BPS states on a 3-brane probe in the 7-brane background associated with N = 2 SU(2) Super-Yang-Mills theory. These states introduce a second curve of marginal stability, across which some of them decay. Moduli space is therefore divided into four regions, each containing a different stable particle spectrum.