Msugra at a 500-gev Linear Collider

A study is made of what SUSY signals would be observable for mSUGRA models in a 500-GeV linear collider. All current experimental bounds on the mSUGRA parameter space are imposed. For m0 < 1 TeV (or alternately if the current gμ − 2 anomaly maintains) the only observable signals that remain are slepton pair production and neutralino production of χ̃ 2 + χ̃ 1 . Slepton pair production can occur for masses < 250 GeV which for the selectron and smuon pairs require tanβ < 40. In this domain very accurate selectron and smuon masses could be measured. Light staus, τ̃1, with mass < 250 GeV can be pair produced for any tanβ and the neutralino signal can be seen provided m1/2 < ∼ 400 GeV. However, the detection of these requires a much more complicated analysis due to the fact that the dark matter co-annihilation constraint requires that the τ̃1 and χ̃01 mass difference be < ∼ 15 GeV. The point m1/2 = 360 GeV, A0 = 0, μ > 0 is analyzed in detail, and it is shown that the stau and neutralino signals can be detected provided an active mask down to 2o is used. However, large parts of the mSUGRA parameter space exists where a 500-GeV machine would not be able to see any SUSY signal.