Triplet-Singlet Extension of the MSSM with a 125 Gev Higgs and Dark Matter

Abstract: 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.