Taming the Scalar Mass Problem with a Singlet Higgs Boson
  We investigate the fine-tuning problem in the Standard Model and show that Higgs boson and top quark masses consistent with current experimental bounds cannot be obtained unless one extends the particle spectrum. A minimal extension which achieves this involves addition of a singlet real scalar and one generation of vectorlike fermions. We show that this leads to a phenomenologically viable prediction for the mass of the Standard Model Higgs boson. 
Anirban Kundu and Sreerup Raychaudhuri