II. DISCUSSION Let us comment this computation and show how it is different from the usual one pre- sented in textbooks. Let us recall the essential steps of the “standard procedure”. One first writes the scalar fields φ in the unitary gauge as in (2). Then, for µ 2 < 0 , one finds the minima of the potential V ( φ ) = µ $^{2}$φ † φ + λ ( φ † φ ) $^{2}$, which are of the form | φ | = v √$_{2}$ for v = √ − µ $^{2}$/λ . In the variables ( η, U ) , this implies that η = v √$_{2}$ and that U can be any function with values in SU (2) . This U contains the symmetry of the fundamental configuration of the fields φ . In a quantum approach, this would be the vacuum of the theory. Symmetry breaking enters then the scene to fix by hand a particular value to the U fields . Then, performing a true gauge transformation with u = U (in our notations) yields essentially the same computation as the one presented here. We stress the fact that such a gauge transformation is only possible when the U fields are no longer dynamical variables. Indeed, if they were some of the new variables which parametrize the φ fields, then no gauge transformation with a fixed gauge group element u = U would be possible. The v parameter inserts mass terms in the Lagrangian written in terms of the gauge transformed fields. In this “standard procedure”, the obtained Lagrangian does not support a SU (2) -gauge action because this symmetry is forbidden to act on the scalar fields φ , which are required to be written in the chosen form φ = 1 √$_{2}$ ( 0 v + η ′ ) . This is indeed the meaning of the fact that U is fixed once and for all in order that it can be removed by a true gauge transformation. In our computation, there is a clear separation between what happens to fields variables and the genesis of mass terms . Indeed, the requirement µ 2 < 0 is not necessary to obtain and to reveal the field content in terms of photon fields ( A$_{µ}$ ), charged and neutral current fields ( W ± µ , Z$_{µ}$ ), neutrino and electron fields ( ν$_{L}$ , e$_{L}$ , e$_{R}$ ). The Lagrangian obtained in (8) is written for any values of µ $^{2}$. As a consequence, the Lagrangian (8) does contain two phases: one where the fields W ± µ , Z$_{µ}$ and e$_{L}$ + e$_{R}$ get masses and one where these fields remain massless. In the phase µ 2 < 0 , finding the minimum of the potential V ( η ) = µ $^{2}$η$^{2}$+ λη 4 of the field η in (8) yields the unique solution of the form η = v √$_{2}$ . It is unique because η is constrained to be real and positive. It is then convenient to perform a development of η around this 9