Paper detail

Prospects for Higgs coupling measurements in SUSY with radiatively-driven naturalness

In the post-LHC8 world-- where a Standard Model-like Higgs boson has been established but there is no sign of supersymmetry (SUSY)-- the detailed profiling of the Higgs boson properties has emerged as an important road towards discovery of new physics. We present calculations of the expected deviations in Higgs boson couplings $κ_{τ,b}$, $κ_t$, $κ_{W,Z}$, $κ_g$ and $κ_γ$ versus the naturalness measure $Δ_{\rm EW}$. Low values of $Δ_{\rm EW}\sim 10-30$ give rise to a natural Little Hierarchy characterized by light higgsinos with a mass of $μ\sim m_Z$ while top squarks are highly mixed but lie in the several TeV range. For such models with radiatively-driven naturalness, one expects the Higgs boson $h$ to look very SM-like although deviations can occur. The more promising road to SUSY discovery requires direct higgsino pair production at a high energy $e^+e^-$ collider operating with the center-of-mass energy $\sqrt{s}>2μ\sim \sqrt{2Δ_{\rm EW}}m_Z$.