Finite supersymmetric grand unified theory reexamined

We analyze the finite supersymmetric SU(5) grand unified model taking into account the threshold corrections at the grand unified theory and supersymmetry breaking scales and the problem of electroweak symmetry breaking which is particularly important in the case of large tan beta. We find that there are still parameter regions where the low-energy experimental values are consistently reproduced and the Higgs potential parameters actually satisfy both constraints for large tan beta and radiative electroweak symmetry breaking, provided that a new free parameter is introduced in the boundary condition of the Higgs soft-mass parameter, while it preserves the finiteness requirements.