Neutralino Proton Cross Sections For Dark Matter In SUGRA And D-BRANE Models

Neutralino proton cross sections are examined for models with R-parity invariance with universal soft breaking (mSUGRA) models, nonuniversal SUGRA models, and D-brane models. The region of parameter space where current dark matter detectors are sensitive, i.e. $1\times 10^{-6}$ pb, is examined. For mSUGRA models, detectors are sampling parts of the parametr space for tan$\beta >\sim 25$. The nonuniversal models can achieve cross sections that are a factor of 10-100 bigger or smaller then the universal one and in the former case sample regions tan$\beta >\sim 4$. The D-brane models considered require tan$\beta >\sim 15$. The inclusion of CP violating phases reduces the cross section by a factor of $\sim$ 2-3 (but also requires considerable fine tuning at the GUT scale). The expected particle spectra at accelerators are examined and seen to differ for each model. Three new regions of possible coannihilation are noted.