 Dynamical symmetry breaking (DSB). In such theories as the unified model of electroweak interactions, the SSB responsible (via the Higgs mechanism) for the masses of the gauge vector bosons is because of the symmetry-violating vacuum expectation values of scalar fields (the so-called Higgs fields) introduced ad hoc in the theory. For different reasons — first of all, the initially ad hoc character of these scalar fields for which there was no experimental evidence until the results obtained in July 2012 at the LHC — some attention has been drawn to the possibility that the Higgs fields could be phenomenological rather than fundamental, that is bound states resulting from a specified dynamical mechanism. SSB realized in this way has been called  “DSB”.[18]