[en] The reconstruction of the Higgs potential in the minimal supersymmetric standard model (MSSM) requires the measurement of the trilinear Higgs self-couplings. The 'double Higgs production' subgroup has been investigating the possibility of detecting signatures of processes carrying a dependence on these vertices at the large hadron collider (LHC) and future linear colliders (LCs). As reference reactions, we have chosen gg → hh and e⁺e^- → hhZ, respectively, where h is the lightest of the MSSM Higgs bosons. In both cases, the Hhh interaction is involved. For m_H >or∼ 2 m_h, the two reactions are resonant in the H → hh mode, providing cross sections which are detectable at both accelerators and strongly sensitive to the strength of the trilinear coupling involved. We explore this mass regime of the MSSM in the h → bb decay channel, also accounting for irreducible background effects. (orig.)

[en] The status of two on-going studies concerning important aspects of the phenomenology of gauge-mediated supersymmetry breaking (GMSB) models at TeV colliders is reported. The first study deals with the characteristics of the light Higgs boson spectrum allowed by the (minimal and non-minimal) GMSB framework. Today's most accurate GMSB model generation and two-loop Feynman-diagrammatic calculation of m_h have been combined. The Higgs masses are shown in dependence of various model parameters at the messenger and electroweak scales. In the minimal model, an upper limit on m_h of about 124 GeV is found for m_t=175 GeV. The second study is focused on the measurement of the fundamental SUSY breaking scale √(F) at the LHC in the GMSB scenario where a stau is the next-to-lightest SUSY particle (NLSP) and decays into a gravitino with cτ_NLSP in the range 0.5 m to 1 km. This implies the measurement of mass and lifetime of long lived sleptons. The identification is performed by determining the time of flight in the ATLAS muon chambers. Accessible range and precision on √(F) achievable with a counting method are assessed. (orig.)