HET SEMINAR<br>Solitons on Intersecting D3-Branes

Recently, Mintun, Polchinski, and Sun highlighted a subtlety in the effective description of a system of pair of D3-branes intersecting/overlapping in 1+1 dimension.  The issue they focused on was the existence/absence of solitons corresponding to D-string stretched between the D3-branes, which is expected to exist by S-duality (since the state corresponding to the F-string is included in the effective description.) We show that the subtleties identified by Mintun et.al. goes away if the angle between the D3-branes are scaled in a certain way as the alpha'->0 limit is taken.  In our scaling, the UV pathology encountered by Mintun et.al. is regulated by a tower of massive states whose spectrum and interaction is computable.