Search for a realistic string model at LHC

Abstract

We survey the low-energy supersymmetry phenomenology of a three-family Pati-Salam model constructed from intersecting $D6$-branes in Type IIA string theory on the ${\mathbf{T}}^{\mathbf{6}}/({\mathbb{Z}}_{\mathbf{2}}\ifmmode\times\else\texttimes\fi{}{\mathbb{Z}}_{\mathbf{2}})$ orientifold which possesses many of the phenomenological properties desired in string model building. In the model, there is no exotic matter in the low-energy spectrum, the correct mass hierarchies for quarks and leptons may be obtained, and the gauge couplings are automatically unified at the string scale. We calculate the supersymmetry breaking soft terms and the corresponding low-energy supersymmetry particle spectra for the model. We find the WMAP constrained dark-matter density can be generated in this model in the stau-neutralino and chargino-neutralino coannihilation regions, with expected final states at LHC consisting of low-energy leptons and $\mathcal{O}\text{ }\text{ }(\mathrm{GeV})$ neutrinos. Moreover, we expect final states in the supercritical string cosmology scenario to comprise high energy leptons and $\mathcal{O}\text{ }\text{ }(\mathrm{GeV})$ neutrinos.