Dark matter and Consequences of SUSY

Abstract

We examine here the constraints from the amount of relic density of neutralino dark matter and other experiments have on the SUSY parameter space for the mSUGRA model and for models with non-universal soft breaking at the GUT scale. In mSUGRA, the allowed amount of dark matter restricts the SUSY parameter space to a narrow band in m_0 - m_{1/2} (except at very large \tan\beta). The Higgs mass and b-> s\gamma constraints produce a lower bound of m_{1/2}>~{\sim} 300GeV and if the muon magnetic moment anomaly can be interpreted as a 3\sigma deviation from the Standard Model, one also obtains an upper bound of m_{1/2} <~900 GeV, making the SUSY spectrum well accessible to the LHC. The B_s->\mu \mu decay is seen to be accessible to the Tevatron Run2B with 15 fb^{-1} for \tan\beta>~30. However, only parts of the spectrum will be accessible to the NLC if it's energy is below 800GeV. Non-universal soft breaking opens new regions of parameter space. Thus the m_{1/2} lower bound constraint of b->s\gamma and also the Higgs mass can be reduced greatly if the gluino mass is assumed larger at the GUT scale (allowing for a lighter gaugino spectrum), and non-universal Higgs soft breaking masses at the GUT scale can open new allowed regions at relatively low m_{1/2} and high m_0 where dark matter detection cross sections may be increased by a factor of ten or more.