Testing Supersymmetry at Energy-Frontier Colliders

1.We study three-body decays of charginos in supersymmetry and examine the dependence of the decay rates on the mass of scalar quarks and leptons.We find that a heavy sfermion can influence the rate drastically if the chargino is gaugino-like，even if the two-body decay channel to W is open。Study of the final state leptons and jets will be useful to extract the sfermion mass from the data.2。Supersymmetric relation between coupling constants receive corrections from soft-breaking sfermion masses and may be useful to obation information on very heavy sfermions.We study its effect in chargino pair production in e i D1 I D 1 e I D1-I D 1 annihilation.3。We find that the decay of third-generation sfermions to final states containing a gauge or Higgs boson can have a substantial branching fration.4。Lepton number breaking top quark interaction can appear in R-parity breaking supersymmetric models。We calculate its effect in top pair production at the Tevatron and find that top polarization and forward-backward asymmetry are useful observables to improve the limit on the coupling.5。We study the distribution of lepton pairs in the decay of the second lightest neutralino at the LHC，as a means to determine the mass difference。We find that the distribution is very sensitive to the model parameters。

1. We study three-body decays of charginos in supersymmetry and examine the dependence of the decay rates on the mass of scalar quarks and leptons. We find that a heavy sfermion can influence the rate drastically if the chargino is gaugino-like, even if the two-body decay channel to W is open. Study of the final state leptons and jets will be useful to extract the sfermion mass from the data.2. Supersymmetric relation between coupling constants receive corrections from soft-breaking sfermion masses and may be useful to obation information on very heavy sfermions. We study its effect in chargino pair production in eィイD1+ィエD1eィイD1-ィエD1 annihilation.3. We find that the decay of third-generation sfermions to final states containing a gauge or Higgs boson can have a substantial branching fration.4. Lepton number breaking top quark interaction can appear in R-parity breaking supersymmetric models. We calculate its effect in top pair production at the Tevatron and find that top polarization and forward-backward asymmetry are useful observables to improve the limit on the coupling.5. We study the distribution of lepton pairs in the decay of the second lightest neutralino at the LHC, as a means to determine the mass difference. We find that the distribution is very sensitive to the model parameters.