[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 model with the SU(2)_L x SU(2)_R x U(1)_B-L gauge group, containing one bidoublet and two triplets in the Higgs sector, is considered. The link between the constants determining the physical Higgs boson interactions and the neutrino oscillation parameters is found. It is shown that the observation of the ultrahigh-energy neutrinos with the help of the processes e^-ν_e→W^-Z, e^-ν_e→μ^-ν_μ, gives us information on the singly charged Higgs bosons. The processes of the doubly charged Higgs boson production, e^-μ^-→Δ^(--)₁γ, e^-μ^-→Δ^(--)₁Z, are investigated. From the point of view of detecting the neutral Higgs bosons the process of the electron-muon recharge e^-μ⁺→e⁺μ^- is studied. (orig.)