Features of Fermion Dynamics Revealed by SU2 Symmetry

We deal here with the notion of statistical order and apply it to a system of interacting fermions endowed with an SU2 x SU2 symmetry. The discussion takes place in a thermal quantum statistical scenario. Two distinct fermion-fermion interactions are at play. One of them is a well-known spin-flip interaction. The other is the pairing interaction responsible for nuclear superconductivity. We used novel statistical quantifiers that yield insights regarding changes in the statistical order produced when the values of the pertinent coupling constants vary. In particular, we show that judicious manipulation of the energy cost associated with statistical order variations with the fermion number is the key to understanding important details of the associated dynamics.