Constrained standard model from a compact extra dimension

Abstract

An SU(3)\ifmmode\times\else\texttimes\fi{}SU(2)\ifmmode\times\else\texttimes\fi{}U(1) supersymmetric theory is constructed with a TeV-sized extra dimension compactified on the orbifold ${S}^{1}{/(Z}_{2}\ifmmode\times\else\texttimes\fi{}{Z}_{2}^{\ensuremath{'}}).$ The compactification breaks supersymmetry leaving a set of zero modes that correspond precisely to the states of the 1 Higgs doublet standard model. Supersymmetric Yukawa interactions are localized at orbifold fixed points. The top quark hypermultiplet radiatively triggers electroweak symmetry breaking, yielding a Higgs potential that is finite and exponentially insensitive to physics above the compactification scale. This potential depends on only a single free parameter, the compactification scale, yielding a Higgs boson mass prediction of 127\ifmmode\pm\else\textpm\fi{}8 GeV. The masses of all the superpartners and the Kaluza-Klein excitations are also predicted. The lightest supersymmetric particle is a top squark of mass $197\ifmmode\pm\else\textpm\fi{}20$ GeV. The top Kaluza-Klein tower leads to the $\ensuremath{\rho}$ parameter having quadratic sensitivity to unknown physics in the ultraviolet region.