[en] The present work takes up the problem of finding the absolute minimum of a SO(N)-invariant Higgs potential for the reducible representation of Higgs fields consisting of the antisymmetric (A) and symmetric (S) traceless second-rank tensors. The stability of the minimum under changes on the potential's parameters is also investigated. Potentials containing S alone, both A and S coupled by a positive semi-definite term are minimized. Eigenstates of the Higgs mass matrix are calculated and related to the behavior of the SO(N)-action. Previous results relying on the absence of pseudo-Goldstone models and a new application of the geometry of the action show that the minimum is stable under small changes of the parameters. It is thus stable in an open region of the full eleven-dimensional parameter space of the most general potential of its kind. The isotropy group of the minimum is found to be either SO(N-p) x SO(p-2) x SO(2) or U({N-p}/2) x U(p/2), and the relative magnitudes of the vacuum expectation values of A and S are not constrained. For SO(10), U(3) x U(2) contains the standard model. One-loop Renormalization Group β-functions are calculated for all parameters of the model

[en] Fusion cross sections have been measured for the ²⁸Si + ¹²C system over the energy range 60 MeV <= E²⁸ Si <= 90 MeV. Large structures in the total fusion yield are identified at Esub(cm) = 19.6, 20.6, 22.0, 23.9 and 25.1 MeV. Unlike most systems previously studied, the nucleon decay modes are largely responsible for these anomalies. The structures occur at successive integral values of angular momentum, but do not appear to correlate with known resonances in 180⁰ elastic and inelastic scattering. (orig.)