Triplet-Singlet Extension of the MSSM with a 125 Gev Higgs and Dark
  Matter
  We study the extension of Minimal Supersymmetric Standard Model by adding one
singlet and one hypercharge zero SU(2) triplet chiral superfield. The triplet
sector gives an additional contributions to the scalar masses and we find that
the lightest CP-even Higgs boson can have a mass of 119-120 GeV at the tree
level, and radiative correction raises the value to 125 GeV. In this model no
significant contributions from stop loops is needed to get the required Higgs
mass which alleviates the fine tuning problem of fixing the stop mass to a high
precision at the GUT scale. In addition this model gives a neutralino dark
matter of mass around 100 GeV which is a mixture of Higgsino and Triplino with
a dark matter density consistent with WMAP observations. The spin-independent
scattering cross-section with nucleons is 10^(-43) cm^2, which makes it
consistent with the bounds from direct detection experiments like XENON100 and
others.
