The Supersymmetric Standard Model, with a Brout-Englert-Higgs boson as spin-0 partner of the Z

Abstract

Supersymmetric extensions of the standard model lead us to expect superpartners for all particles, spin-0 squarks and sleptons and spin-1/2 gluinos, charginos and neutralinos, with an odd R-parity making the lightest one stable. The electroweak breaking is induced by a pair of spin-0 doublets, leading to several charged and neutral BE-Higgs bosons. These theories also lead to gauge/Higgs unification by providing spin-0 bosons as extra states for spin-1 gauge bosons within massive gauge multiplets. In particular, the 125 GeV boson recently observed at CERN, most likely a BE-Higgs boson associated with the electroweak breaking, may also be interpreted, up to a mixing angle induced by supersymmetry breaking, as the spin-0 partner of the Z under two supersymmetry transformations. We also discuss how the compactification of extra dimensions, relying on R-parity and other discrete symmetries, may determine both the grand-unification and supersymmetry-breaking scales.