“…At a fundamental level, sigma fields φ describe the dynamics of Goldstone bosons in spontaneously broken field theories like the Standard Model of electroweak interactions. The frozen-Higgs possibility (4) has been explored in the literature [31,32,33,34,35], providing a Higgs-less mechanism to supply mass to the electro-weak gauge vector bosons W ± and Z through a coupling to a U(2)-invariant NLSMà la Stueckelberg [36]. Unfortunately, the recent "discovery" of a particle consistent with the Higgs boson, together with some apparent insoluble dichotomy "unitarity-renormalizability" [37] of the NLSM Higgs-less approach, have diminished importance to this program.…”