UC Irvine

We show that a 125GeV Higgs boson and percent-level fine-tuning are simultaneously attainable in the minimal supersymmetric standard model, with no additional fields and supersymmetry breaking generated at the grand unification theory scale. The Higgs mass is raised by large radiative contributions from top squarks with significant left-right mixing, and naturalness is preserved by the focus point mechanism with large A-terms, which suppresses large log-enhanced sensitivities to variations in the fundamental parameters. The focus point mechanism is independent of almost all supersymmetry-breaking parameters, but is predictive in the top sector, requiring the grand unification theory-scale relation mH u2:mU 32:mQ 32:At2=1:1+x-3y:1-x:9y, where x and y are constants. We derive this condition analytically and then investigate three representative models through detailed numerical analysis. The models generically predict heavy superpartners, but dark matter searches in the case of nonunified gaugino masses are promising, as are searches for top squarks and gluinos with top- and bottom-rich cascade decays at the LHC. This framework may be viewed as a simple update to mSUGRA/CMSSM to accommodate both naturalness and current Higgs boson constraints, and provides an ideal framework for presenting new results from LHC searches. © 2012 American Physical Society.