Split extended supersymmetry from intersecting branes

We study string realizations of split extended supersymmetry, recently proposed in [I. Antoniadis, et al. hep-ph/0507192]. Supersymmetry is broken by small (c) deformations of intersection angles of D-branes giving tree-level masses of order m(0)(2) similar to is an element of M-s(2), where M-s is the string scale, to localized scalars. We show through an explicit one-loop string amplitude computation that gauginos acquire hierarchically smaller Dirac masses m(1/2)(D) similar to m(0)(2)/M-s. We also evaluate the one-loop higgsino mass, A, and show that, in the absence of tree-level contributions, it behaves as mu similar to m(0)(4)/M-s(3). Finally we discuss an alternative suppression of scales using large extra dimensions. The latter is illustrated, for the case where the gauge bosons appear in N = 4 representations, by an explicit string model with Standard Model gauge group, three generations of quarks and leptons and gauge coupling unification. (c) 2006 Elsevier B.V. All rights reserved.