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SU(5) × SU(5) unification revisited

  • David Emmanuel-CostaEmail author
  • Edison T. Franco
  • Ricardo González Felipe
Article

Abstract

The idea of grand unification in a minimal supersymmetric SU(5) × SU(5) framework is revisited. It is shown that the unification of gauge couplings into a unique coupling constant can be achieved at a high-energy scale compatible with proton decay constraints. This requires the addition of a minimal particle content at intermediate energy scales. In particular,the introduction of the SU(2)L triplets belonging to the \( \left( {15 + 1} \right) + \left( {\overline {15} + 1} \right) \) representations, as well as of the scalar triplet Σ3 and octet Σ8 in the (24, 1) representation, turns out to be crucial for unification. The masses of these intermediate particles can vary over a wide range, and even lie in the TeV region. In contrast, the exotic vector-like fermions must be heavy enough and have masses above 1010 GeV. We also show that, if the SU(5) × SU(5) theory is embedded into a heterotic string scenario, it is not possible to achieve gauge coupling unification with gravity at the perturbative string scale.

Keywords

Supersymmetric gauge theory Gauge Symmetry GUT 

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Copyright information

© SISSA, Trieste, Italy 2011

Authors and Affiliations

  • David Emmanuel-Costa
    • 1
    Email author
  • Edison T. Franco
    • 1
    • 2
  • Ricardo González Felipe
    • 3
    • 1
  1. 1.Departamento de Física and Centro de Física Teórica de Partículas, Instituto Superior TécnicoUniversidade Técnica de LisboaLisboaPortugal
  2. 2.Instituto de Física Gleb WataghinUniversidade Estadual de CampinasCampinas, SPBrazil
  3. 3.Instituto Superior de Engenharia de LisboaLisboaPortugal

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