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arXiv · hep-th/9908072

Tachyon-free Non-supersymmetric Type IIB Orientifolds via Brane-Antibrane Systems

G. Aldazabal·A. M. Uranga
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Abstract

We derive the rules to construct type IIB compact orientifolds in six and four dimensions including D-branes and anti-D-branes. Even though the models are non-supersymmetric due to the presence of the anti-D-branes, we show that it is easy to construct large classes of models free of tachyons. Brane-antibrane annihilation can be prevented for instance by considering models with branes and antibranes stuck at different fixed points in the compact space. We construct several anomaly-free and tachyon-free six-dimensional orientifolds containing D9-branes and anti-D5-branes. This setup allows to construct four-dimensional chiral models with supersymmetry unbroken in the bulk and in some D-brane sectors, whereas supersymmetry is broken (at the string scale) in some `hidden' anti-D-brane sector. We present several explicit models of this kind. We also comment on the role of the non-cancelled attractive brane-antibrane forces and the non-vanishing cosmological constant, as providing interesting dynamics for the geometric moduli and the dilaton, which may contribute to their stabilization.

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G. Aldazabal, A. M. Uranga. 1999-10-13. Tachyon-free Non-supersymmetric Type IIB Orientifolds via Brane-Antibrane Systems. https://doi.org/10.1088/1126-6708%2F1999%2F10%2F024

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