WMAP constraints, supersymmetric dark matter, and implications for the direct detection of supersymmetry

Recently WMAP has measured the cosmological parameters to a much greater accuracy. We analyze the implications of this more precise measurement for supersymmetric dark matter and for the direct detection of supersymmetry at accelerators. We consider MSUGRA including also the hyperbolic branch (HB) in the radiative breaking of the electroweak symmetry. On the part of the hyperbolic branch where the lightest neutralino is dominantly a Higgsino rather than being mostly a B-ino, the relic density constraints are satisfied by coannihilation with the next lightest neutralino and the light chargino. Including this branch the lightest neutralino mass satisfies $m_{{\chi }_1^0}<~1200\mathrm{GeV}$ for $\tan \beta <~50.$ Constraints of $\overrightarrow{b}s+\gamma ,$ of $g_{\mu }-2,$ and of $B_s^0\to {\mu }^{+}{\mu }^{-}$ are also analyzed. It is shown that the neutralino-proton cross section in each case will fall within the reach of dark matter experiments. The possibility for the direct detection of supersymmetry is discussed in the allowed regions of the parameter space consistent with WMAP constraints. A brief discussion of the hyperbolic branch and focus point region (HB/FP) is also given.