On SU(3)F positive-parity octet and decuplet baryons

A continuum approach to the three valence-quark bound-state problem in quantum field theory, employing parametrisations of the necessary kernel elements, is used to compute the spectrum and Poincarö- covariant wave functions for all flavour-SU(3) octet and decuplet baryons and their first positive-parity ex citations. Such analyses predict the existence of nonpointlike, dynamical quark-quark (diquark) correlations within all baryons; and a uniformly sound description of the systems studied is obtained by retaining flavour- antitriplet-scalar and flavour-sextet-pseudovector diquarks. The analysis predicts the existence of positive- parity excitations of the 𝚵, 𝚵*, Ω baryons, with masses, respectively (in GeV): 1.84(08), 1.89(04), 2.05(02). These states have not yet been empirically identified. This body of analysis suggests that the expression of emergent mass generation is the same in all u, d, s baryons and, notably, that dynamical quark-quark correla tions play an essential role in the structure of each one. It also provides the basis for developing an array of predictions that can be tested in new generation experiments.

Electromagnetic form factors of nucleon resonances from CLAS

Exclusive single and double meson photo- and electroproduction reactions are the largest sources of information on the spectrum and structure of nucleon resonances. The excited states of the nucleon manifest as a complex interplay between the inner core of three dressed quarks and the external meson-baryon cloud. Various N* with distinctively different structure appear as unique laboratory where many features of strong QCD can be explored. With combination of nearly 4π acceptance of the CLAS detector and continuous electron beam (Jefferson Lab, USA) it is possible to obtain physics observables of the major reaction channels in the N* excitation region. The results on the electromagnetic transition form factors of N(1440)1/2+ and N(1520)3/2- are presented.