Mass hierarchy from recoiling D-branes

Using conformal field theory methods we construct a metric that describes the distortion of space-time surrounding a D~irichlet!-brane ~solitonic! defect after being struck by another D-brane. By viewing our four-dimensional universe as such a struck brane, embedded in a five-dimensional space-time, we argue on the appearance of a band of massive Kaluza-Klein excitations for the bulk graviton which is localized in a region of the fifth dimension determined by the inverse size of the band. The band incorporates the massless mode ~ordinary graviton! and its thickness is determined essentially by the width of the Gaussian distribution describing the ~target-space! quantum fluctuations of the intersecting-brane configuration.