Gauge Coupling Unification in the Exceptional Supersymmetric Standard Model

Abstract

We consider the renormalisation group flow of gauge couplings within the so-called exceptional supersymmetric standard model (E${}_6$SSM) based on the low energy matter content of 27 dimensional representations of the gauge group $E_6$, together with two additional non-Higgs doublets. The two--loop beta functions are computed, and the threshold corrections are studied in the E${}_6$SSM. Our results show that gauge coupling unification in the E${}_6$SSM can be achieved for phenomenologically acceptable values of ${\alpha }_3(M_Z)$, consistent with the central measured low energy value, unlike in the minimal supersymmetric standard model (MSSM) which, ignoring the effects of high energy threshold corrections, requires significantly higher values of ${\alpha }_3(M_Z)$, well above the experimentally measured central value.

15 pages, 1 figure, references added, section 4 expanded, table added

Cited by in corpus (5)

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• Mirror World with Broken Mirror Parity, E(6) Unification and Cosmology
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• Generation of Flavour Dependent Lepton Asymmetries in the E${}_6$SSM