Precise focus point scenario for a natural Higgs boson in the MSSM
  A small Higgs mass parameter m_{h_u}^2 can be insensitive to various trial heavy stop masses, if a universal soft squared mass is assumed for the chiral superpartners and the Higgs boson at the grand unification (GUT) scale, and a focus point (FP) of m_{h_u}^2 appears around the stop mass scale. The challenges in the FP scenario are (1) a too heavy stop mass (~ 5 TeV) needed for the 126 GeV Higgs mass and (2) the too high gluino mass bound (> 1.4 TeV). For a successful FP scenario, we consider (1) a superheavy right-hand (RH) neutrino and (2) the first and second generations of hierarchically heavier chiral superpartners. The RH neutrino can move a FP in the higher energy direction in the space of (Q, m_{h_u}^2(Q)), where Q denotes the renormalization scale. On the other hand, the hierarchically heavier chiral superpartners can lift up a FP in that space through two-loop gauge interactions. Precise focusing of m_{h_u}^2(Q) is achieved with the RH neutrino mass of ~ 10^{14} GeV together with an order one (0.9-1.2) Dirac Yukawa coupling to the Higgs boson, and the hierarchically heavy masses of 15-20 TeV for the heavier generations of superpartners, when the U(1)_R breaking soft parameters, m_{1/2} and A_0 are set to be 1 TeV at the GUT scale. Those values can naturally explain the small neutrino mass through the seesaw mechanism, and suppress the flavor violating processes in supersymmetric models. 
Bumseok Kyae, Chang Sub Shin
hep-ph