On Realistic Brane Worlds from Type I Strings
Abstract
We review recent progress in constructing realistic brane models from type I string vacua. Explicit models with three families of the standard model gauge group and its leftright generalizations are presented with supersymmetry broken at the string scale of order $M_s\sim 10^{1012}$ GeV, realizing gravity mediated supersymmetry breaking at low energies. Unification of couplings occurs at the string scale due to the particular U(1) normalizations of Dbranes, as well as to the existence of a Higgs field per family of quarks and leptons. The proton is naturally stable due to intrinsic discrete symmetries of the corresponding string theory. In particular Rparity appears as a natural stringy symmetry. There are axionic fields with the right couplings as to solve the strong CP problem. Similar realizations are also presented for a string scale of 1 TeV, although without solving the gauge unification problem. Open questions are briefly discussed.
 Publication:

arXiv eprints
 Pub Date:
 May 2000
 arXiv:
 arXiv:hepph/0005033
 Bibcode:
 2000hep.ph....5033A
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 8 pages, plenary talk by FQ at PASCOS 99