Non-Universal Gaugino Masses and Natural Supersymmetry
  We demonstrate that natural supersymmetry is readily realized in the framework of SU(4)_c \times SU(2)_L \times SU(2)_R with non-universal gaugino masses. Focusing on ameliorating the little hierarchy problem, we explore the parameter space of this model which yields small fine-tuning measuring parameters (natural supersymmetry) at the electroweak scale (\Delta_{EW}) as well as at high scale (\Delta_{HS}). It is possible to have both \Delta_{EW} and \Delta_{HS} less than 100 in these models, (2 % or better fine-tuning), while keeping the light CP-even (Standard Model-like) Higgs mass in the 123 GeV-127 GeV range. The light stop quark mass lies in the range 700 GeV <m_{\tilde{t}_{1}}< 1500 GeV, and the range for the light stau lepton mass is 900 GeV <m_{\tilde{\tau}_{1}}< 1300 GeV. The first two family squarks are in the mass range 3000 GeV <m_{\tilde{t}_{1}}< 4500 GeV, and for the gluino we find 2500 GeV <m_{\tilde{g}_{1}}< 3500 GeV. We do not find any solution with natural supersymmetry which yields significant enhancement for Higgs production and decay in the diphoton channel. 
Ilia Gogoladze, Fariha Nasir, Qaisar Shafi
hep-ph