SU(5)_{flip} x SU(5)' from Z_{12-I}

TL;DR

This paper constructs a flipped-SU(5) model from Z_{12-I} heterotic string compactification, achieving realistic features like three families, doublet-triplet splitting, and dynamical supersymmetry breaking, with gauge symmetry enhancement and decoupled exotics.

Contribution

It presents a novel flipped-SU(5) string-derived model with realistic phenomenology, including gauge symmetry enhancement and hidden sector SUSY breaking mechanisms.

Findings

All exotic states are decoupled from low energy physics.

The model achieves sin^2θ_W^0=3/8 at unification.

The hidden sector can confine between 10^{11} and 10^{16} GeV.

Abstract

Based on the Z_{12-I} orbifold compactification of the heterotic string theory, we construct a flipped-SU(5) model with three families of the standard model matter and ingredients for dynamical supersymmetry breaking. The doublet-triplet splittings in the Higgs representations 5_{-2} and \bar{5}_{2} are achieved by the couplings 10_{1}10_{1}5_{-2} and \bar{10}_{-1}\bar{10}_{-1}\bar{5}_{2}, where 10_{1} and \bar{10}_{-1} develop GUT scale vacuum expectation values, breaking the flipped-SU(5) down to the standard model gauge group. In this model, all the exotic states are decoupled from the low energy physics, and sin^2\theta_W^0=3/8. Above the compactification scale, the flipped-SU(5) gauge symmetry is enhanced to the SO(10) gauge symmetry by including the Kaluza-Klein (KK) modes. The hidden sector gauge group is SU(5)'. The threshold correction by the KK modes allow a very wide range for the hidden sector confining scale (10^{11} GeV -- 10^{16} GeV). One family of hidden matter (\bar{10}' and 5') gives rise to dynamical supersymmetry breaking.