Gauginos as a signal for supersymmetry atpp¯colliders

We present a comprehensive analysis of the signals from the pair production of the mass eigenstates (W ̃ \~{}{}, Z ̃ \~{}{}, and {γ} ̃ \~{}{}) of the gauge-Higgs-fermion system for both CERN and Fermilab Tevatron energies, assuming that {γ} ̃ \~{}{} is relatively light ({}10 GeV) and escapes detection. The effect of varying the mixings and the mass spectrum of the scalar fermions is also discussed for a general minimal supersymmetry model, assuming only that {γ} ̃ \~{}{} is light. Signals from both the hadronic and leptonic decays of W ̃ \~{}{} and Z ̃ \~{}{} are studied, incorporating cuts, triggers, and experimental resolutions appropriate to the UA1 detector and Collider Detector at Fermilab. We show that if the decays W{→}W ̃ \~{}{}Z ̃ \~{}{} and Z⁰{→}W ̃ \~{}{}W ̃ \~{}{}{} are kinematically accessible, there is a substantial level of (i) jet(s) + p/T events from the hadronic decays of W ̃ \~{}{} and Z ̃ \~{}{}, (ii) a comparable level of background-free multilepton + p/T events, essentially free from hadronic activity from the leptonic decay of W ̃ \~{}{} and Z ̃ \~{}{}, and (iii) jet(s) + lepton(s) + p/T events from the leptonic decay of one of the gauginos and hadronic decay of the other. We present rates and distributions for these events and show that a conclusive absence of such a signal could lead to more stringent direct mass limits on masses of the W ̃ \~{}{} and Z ̃ \~{}{} than are currently available.Absence of multilepton signals implies m_W ̃ \~{}36--38 GeV, corresponding to m_Z ̃ \~{}42--44 GeV, whereas the recently announced UA1 limit on the sequential-heavy-lepton mass translates to m_W ̃ \~{}40--44 GeV, corresponding to m_Z ̃ \~{}45--50 GeV. We have also studied the signals from the decays of W ̃ \~{}{} produced in association with {γ} ̃ \~{}{}. Although we find a substantial rate for jet(s) + p/T events, conclusions based on this signal would entail a study of the substantial standard-model backgrounds. We also conclude that the single lepton + p/T signal from the leptonic decay of W ̃ \~{}{} would be very difficult to separate from the standard-model background from W{→}l{ν}{} and W{→}l{ν}{ν}{} {ν}{}. .AE