Supersymmetric SU(5) model with large supersymmetry breaking scale

Abstract

Taking into account uncertainties related with the initial coupling constants and threshold corrections at low and high scales we find that in standard supersymmetric SU(5) model the supersymmetry breaking scale could be up to $10^8$ GeV. In the extensions of the standard supersymmetric SU(5) model the supersymmetry breaking scale could be up to $O(10^{12})$ GeV. In standard SU(5) supersymmetric model it is possible to increase the GUT scale up to $5 \cdot 10^{17}$ GeV provided that the masses of chiral superoctets and supertriplets are $m_{3,8} \sim O(10^{13})$ GeV. For SU(5) supersymmetric model with $10^6$ GeV $\leq M_{SUSY} \leq 10^8$ GeV the Higgs boson mass is predicted to be 120 GeV $\leq m_h \leq $ 150 GeV.