Lawrence J. Hall, David Pinner, Joshua T. Ruderman
The naturalness of a Higgs boson with a mass near 125 GeV is explored in a
variety of weak-scale supersymmetric models. A Higgs mass of this size strongly
points towards a non-minimal implementation of supersymmetry. The Minimal
Supersymmetric Standard Model now requires large A-terms to avoid multi-TeV
stops. The fine-tuning is at least 1% for low messenger scales, and an order of
magnitude worse for high messenger scales. Naturalness is significantly
improved in theories with a singlet superfield S coupled to the Higgs
superfields via \lambda\ S H_u H_d. If \lambda\ is perturbative up to unified
scales, a fine-tuning of about 10% is possible with a low mediation scale.
Larger values of \lambda, implying new strong interactions below unified
scales, allow for a highly natural 125 GeV Higgs boson over a wide range of
parameters. Even for \lambda\ as large as 2, where a heavier Higgs might be
expected, a light Higgs boson naturally results from singlet-doublet scalar
mixing. Although the Higgs is light, naturalness allows for stops as heavy as
1.5 TeV and a gluino as heavy as 3 TeV. Non-decoupling effects among the Higgs
doublets can significantly suppress the coupling of the light Higgs to b quarks
in theories with a large \lambda, enhancing the \gamma \gamma\ and WW signal
rates at the LHC by an order one factor relative to the Standard Model Higgs.
View original:
http://arxiv.org/abs/1112.2703
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