Radiative natural supersymmetry with mixed axion/higgsino cold dark
  matter
  Models of natural supersymmetry seek to solve the little hierarchy problem by
positing a spectrum of light higgsinos \lesssim 200 GeV and light top squarks
\lesssim 500 GeV along with very heavy squarks and TeV-scale gluinos. Such
models have low electroweak finetuning and are safe from LHC searches. However,
in the context of the MSSM, they predict too low a value of m(h) and the relic
density of thermally produced higgsino-like WIMPs falls well below dark matter
(DM) measurements. Allowing for high scale soft SUSY breaking Higgs mass
m_{H_u}> m_0 leads to natural cancellations during RG running, and to
radiatively induced low finetuning at the electroweak scale. This model of
radiative natural SUSY (RNS), with large mixing in the top squark sector,
allows for finetuning at the 5-10% level with TeV-scale top squarks and a 125
GeV light Higgs scalar h. If the strong CP problem is solved via the PQ
mechanism, then we expect an axion-higgsino admixture of dark matter, where
either or both the DM particles might be directly detected.
