Standard Model at High Temperatures

Abstract

The article presents a new realization of the hypothesis about the simplification of the gauge group of the Standard Model with increasing the temperature of the Universe, i.e. when moving back in time to the moment of its occurrence. It is assumed that this simplification is achieved by the gauge group contraction with the parameter, that decreases with increasing temperature. The Lagrangian of the Standard Model is divided into terms that differ in powers of the contraction parameter. This makes it possible to arrange in time the stages of development of the Standard Model as the Universe cools. The evolution of the properties of particles and their interactions is based on the explicit form of the intermediate Lagrangians and occurs in a natural order from simpler to more complicated structures, starting from the Planck scale 1019 GeV. The contraction hypothesis of the gauge group of the Standard Model does not contradict LHC experimental data on the Higgs boson production cross sections.