Supersymmetry and Dark Matter
  We examine supergravity models with grand unification at M_G possessing R parity invariance. Current data has begun to significantly constrain the parameter space. Thus for mSUGRA, accelerator data places a lower bound on m_{1/2} of m_{1/2} >~300 GeV while astronomical data on the amount of relic dark matter narrowly determines m_0 in terms of m_{1/2} (for fixed value of tanbeta and A_0) due to co-annihilation effects. Additional new data could fix the parameters further. Thus the parameter space is sensitive to the muon magnetic moment anomaly, \delta a_\mu, and if \delta a_\mu lies 1 \sigma above its current central value, it would exclude mSUGRA, while if it lies 1\sigma below (but is still positive) it pushes the SUSY spectrum into the TeV domain. The B_s ->\mu^+ \mu^- decay is seen to be accessible to the Tevatron RunII with branching ratio sensitivity of Br[B_s ->\mu^+ \mu^-] > 6.5\times10^{-9} with 15 fb^{-1}/detector, and a value of 7(14)\times10^{-8} obtainable with 2 fb^{-1} would be sufficient to exclude mSUGRA for tan beta < 50(55). Measurements of B_s ->\mu^+ \mu^- can cover the full mSUGRA parameter space for tanbeta > 40 if \delta a_\mu > 11\times10^{-10}, and combined measurements of B_s -> \mu^+ \mu^-, a_\mu and m_h (or alternately the gluino mass) would effectively determine the mSUGRA parameters for \mu > 0. Detector cross sections are then within the range of planned future dark matter experiments. Non-universal models are also discussed, and it is seen that detector cross sections there can be much larger, and can be in the DAMA data region. 
R. Arnowitt and B. Dutta