Higgs particles in the adjoint representation of a non-Abelian gauge theory play an important role in many scenarios beyond the standard model, especially grand-unified theories, partial compositeness models, and (broken) supersymmetric theories. However, recently new analytic results based on gauge-invariant perturbation theory have arisen, which require a reevaluation of the observable, physical spectrum of such theories.
Lattice methods are used to determine this spectrum, and test the underlying predictions. To this end, an SU(2) gauge theory with a single adjoint Higgs is simulated. In the Brout-Englert-Higgs phase it is predicted that this theory exhibits a massless, composite and gauge-invariant vector state. This model can then be a well defined way to obtain a low energy QED from a GUT that comprehends it.
It is needed to find simulation points where the Brout-Englert-Higgs effect is present. In these points the physical spectrum as well as the properties of the elementary particles will be investigated in multiple channels. We have found preliminary results about the presence of a massless vector bound state, and also about the phase diagram of the theory.