Tuesday, May 29, 2012

1205.5967 (R. Nevzorov)

E6 inspired SUSY models with exact custodial symmetry    [PDF]

R. Nevzorov
The breakdown of E_6 gauge symmetry at high energies may result in supersymmetric (SUSY) models based on the Standard Model (SM) gauge group together with extra U(1)_{\psi} and U(1)_{\chi} gauge symmetries. To ensure anomaly cancellation the particle content of these E_6 inspired models involves extra exotic states that can give rise to non--diagonal flavour transitions and rapid proton decay. We argue that a single discrete \tilde{Z}^{H}_2 symmetry can be used to forbid tree--level flavor-changing transitions and the most dangerous baryon and lepton number violating operators. We present 5D and 6D orbifold GUT models that can lead to the E_6 inspired SUSY models of this type. The breakdown of U(1)_{\psi} and U(1)_{\chi} gauge symmetries that preserves E_6 matter parity assignment guarantees that the exotic states which originate from 27_i representations of E_6 as well as ordinary quark and lepton states survive to low energies. The considered E_6 inspired models contain at least two dark-matter candidates and must include additional TeV scale vectorlike lepton or vectorlike down type quark states to render the lightest exotic quark unstable. We consider gauge coupling unification in these models and discuss their implications for collider phenomenology and cosmology.
View original: http://arxiv.org/abs/1205.5967

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