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The $gamma^{(ast)}+p to N(1535) tfrac{1}{2}^-$ transition is studied using a symmetry-preserving regularisation of a vector$,otimes,$vector contact interaction (SCI). The framework employs a Poincare-covariant Faddeev equation to describe the initial and final state baryons as quark+di-quark composites, wherein the diquark correlations are fully dynamical, interacting with the photon as allowed by their quantum numbers and continually engaging in breakup and recombination as required by the Faddeev kernel. The presence of such correlations owes largely to the mechanisms responsible for the emergence of hadron mass; and whereas the nucleon Faddeev amplitude is dominated by scalar and axial-vector diquark correlations, the amplitude of its parity partner, the $N(1535) tfrac{1}{2}^-$, also contains sizeable pseudoscalar and vector diquark components. It is found that the $gamma^{(ast)}+p to N(1535) tfrac{1}{2}^-$ helicity amplitudes and related Dirac and Pauli form factors are keenly sensitive to the relative strengths of these diquark components in the baryon amplitudes, indicating that such resonance electrocouplings possess great sensitivity to baryon structural details. Whilst SCI analyses have their limitations, they also have the virtue of algebraic simplicity and a proven ability to reveal insights that can be used to inform more sophisticated studies in frameworks with closer ties to quantum chromodynamics.
In a relativistic quark model we study the structure of the $N(1710)$ resonance, and the $gamma^ast N to N(1710)$ reaction focusing on the high momentum transfer region, where the valence quark degrees of freedom are expected to be dominant. The $N(1
We study the photoproduction of the $N(1440)$ resonance in $gamma^*pto N^*$ process in quark models, where the $N(1440)$ takes different wave functions: first radial excitation of the nucleon imported from low-lying baryon mass spectrum calculations,
Results of a partial wave analysis of new high-statistics data on $gamma pto peta$ from MAMI are presented. A fit using known broad resonances and only standard background amplitudes can not describe the relatively narrow peaking structure in the cro
We study the electromagnetic $Omega_c gamma rightarrowOmega_c^ast$ transition in 2+1 flavor lattice QCD, which gives access to the dominant decay mode of $Omega_c^ast$ baryon. The magnetic dipole and the electric quadrupole transition form factors ar
The form-factors for the transition $ N^*(1535)to N $ induced by isovector and isoscalar axial currents within the framework of light-cone QCD sum rules by using the most general form of the interpolating current are calculated. In numerical calculat