Narrow Results

In this paper, we derive the unitary transformation that relates the chiral basis {R;IJ^PC} to the {I;^2S+1L_J}-basis in a front-form framework. From the most general expression for the Clebsch–Gordan coefficients of the Poincaré group one can see that the chiral limit brings the angular momentum coupling into a simple form that permits the relation in terms of SU(2) Clebsch–Gordan coefficients. We demonstrate that such a transformation is identical to the one obtained for canonical spin in the instant form.

Ken Wilson developed powerful renormalization group procedures for constructing effective theories and solving a broad class of difficult physical problems. His insights allowed him to later advance the Hamiltonian approach to quantum dynamics of particles and fields in the Minkowski space–time, motivated by QCD. The latter advances are described in this article, concluding with a remark on Ken's related interest in difficult systemic issues of society.