  The non-supersymmetric SU(5) model can accommodate heavy neutrinos and gauge
coupling unification when augmented with an adjoint fermionic multiplet 24_F.
Among the most important phenomenological implications of the model is the
prediction of light fermions and scalars, charged under the SU(2) gauge group,
in the reach of the Large Hadron Collider (LHC). In this talk, we report on the
recent calculation of the correlation function between the mass scale of the
new electroweak multiplets and the gauge coupling unification scale at three
loop accuracy.
