The pure Higgs boson sector of the Standard model is modelled by a Klein–Gordon field with a potential, denoted H for this section. The Standard model is a gauge theory and so while the field transforms trivially under the Lorentz group, it transforms as a C 2 -valued vector under the action of the SU ( 2 ) part of the gauge group. Therefore while it is a vector field H : R 1 , 3 → → C 2 , it is still referred to as a scalar field, as scalar describes its transformation (formally, representation) under the Lorentz group. This is also discussed below in the scalar chromodynamics section.