Too many flavours. Dynamical generation of effective degrees of freedom

To check the inflation of new degrees of freedom (strangeness, charm, etc.), which seem necessary for the phenomenological description of elementary particles, it is proposed to interprete the approximate higher symmetries as a consequence of the spontaneous breakdown of a simple basic symmetry group. A mechanism is described - exemplified for model theories with a spontaneously broken basic chiral U1 and isospin SU2 symmetry - by which the extended phenomenological symmetries are generated from the basic symmetry. It essentially consists of an extraction of the Goldstone fields and their canonical conjugate fields from the interaction and appropriate redressings of the basic field generating a proliferated set of dressed fields resembling the ''generations'' of the quark model. The particular proliferation is dictated by the condition of either optimally parametrizing the asymptotic region (''mass fields'') or the local region and the current (''current fields''). In the current scheme the fields all transform like the basic field, whereas in the mass scheme, they are found to transform, in general, only like ray representations of the symmetry group, which allows some novel considerations. Both schemes are connected by a well-defined unitary transformation which reshuffles the Goldstone field dressings and, for the SU2 case, constitutes the origin of the Cabibbo rotation. In the SU2 case for particular values of the parameters the approximate validity of a SU2 x U1 x U1 or SU2 x SU2 x U1 or SU4 symmetry can be established. In contrast to earlier investigations the present paper concentrates on the generation mechanism of new effective fields and their relationships. (author)