Phenomena from intersecting branes in six-dimensional Anti-de Sitter   spacetime
  We relate four-dimensional mass parameters to the positions of AdS 4-brane intersections in six-dimensional AdS spacetime. The 4-branes wrap 1-cycles on the rectangular toroidal orbifold T2/(Z2)3, are situated upon and parallel to the fixed lines, and intersect orthogonally on four-dimensional Minkowski junctions. Particles are arranged upon the line equidistant from the two extra dimensions. In four dimensions, the particles occupy a geometric sequence of mass levels that descends from the Higgs field vacuum expectation value. Scales that we identify with the three Standard Model families derive from the geometry of the orbifold and stand in precise relationship to the GUT scale of the Minimal Supersymmetric Standard Model. 
B. F. Riley