Angular momentum decomposition of chiral multiplets in front form

摘要

In this paper, we derive the unitary transformation that relates the $qar q$ chiral basis {R;IJ ~(PC)} to the {I; ~(2S+1)L _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.