Composition of low-lying J=3/2± Δ-baryons

Lambda Poincare-covariant quark + diquark Faddeev equation is used to develop insights into the structure of the four lightest (I, J(P) =3/2, 3/2 +/-) baryon multiplets. While these systems can contain isovector-axialvector 2 and isovector-vector diquarks, one may neglect the latter and still arrive at a reliable description. The (3/2, 3/2 +/-) states are the simpler systems, with features that bear some resemblance to quark model pictures, e.g., their most prominent rest-frame orbital angular momentum component is S-wave and the Delta(1600)3/2+ may reasonably be viewed as a radial excitation of the Delta(1232)3/+. The (3/2, 3/2-) states are more complex: the Delta(1940)3/2- expresses little of the character of a radial excitation of the Delta(1700)3/2-; and while the rest frame wave function of the latter is predominantly P-wave, the leading piece in the Delta(1940)3/2- wave function is S-wave, in conflict with quark model expectations. Experiments that can test these predictions, such as large momentum transfer resonance electroexcitation, may shed light on the nature of emergent hadron mass.

Automated summary

The Lambda Poincare-covariant quark + diquark Faddeev equation is used to understand the structure of the four lightest baryon multiplets. The (3/2, 3/2 +/-) states exhibit characteristics similar to quark model pictures, while the (3/2, 3/2-) states are more complex.