Related papers: Relations between N and Delta electromagnetic form…
An expansion of the electromagnetic form factors of the nucleon and Delta(1232) in small momentum transfer and pion mass is performed in a manifestly-covariant EFT framework consistent with chiral symmetry and analyticity. We present the…
Without any further adjusting of parameters, a relativistic constituent quark model, successful in the description of the data for the nucleon elastic form factors and of the dominant contribution for the nucleon to Delta electromagnetic…
We present a simple covariant constituent diquark-quark model for the nucleon. The nucleon is assumed to be composed of a scalar diquark and a quark which interact via a quark exchange. Starting from the Bethe-Salpeter equation, the…
We establish relations which express the generalized parton distributions (GPDs) describing the $N\to \Delta$ transition in terms of the nucleon GPDs. These relations are based on the known large-$N_c$ relation between the $N\to \Delta$…
Relations between nucleon, $\Delta$ and nucleon-$\Delta$ electromagnetic properties associated with chiral physics which have been derived in a pure large-$N_c$ limit are greatly modified in a combined large $N_c$ and chiral limits; the…
A brief overview of the recent activity in the measurement of the elastic electromagnetic proton and neutron form factors is presented. It is discussed how the quality of the data has been greatly improved by performing double polarization…
We consider here a manifestly covariant quark model of the nucleon and the Delta, where one quark is off-shell and the other two quarks form an on-shell diquark pair. Using this model, we have shown previously that the nucleon form factors…
The electromagnetic nucleon to Delta transition form factors are evaluated using two degenerate flavors of dynamical Wilson fermions and using dynamical sea staggered fermions with domain wall valence quarks. The two subdominant quadrupole…
We calculate the electric quadrupole to magnetic dipole transition ratio $E2/M1$ for the reaction $\gamma N \ra \Delta(1232)$ in the chiral quark soliton model. The calculated $E2/M1$ ratio is in a good agreement with the very new…
I discuss recent work on nucleon form factors, magnetic strangeness in the nucleon and the isovector nucleon-delta transition based on the broken chiral symmetry of QCD, utilizing recent theoretical developments in ChPT.
In this work, the electromagnetic and gravitational form factors of $\Delta$ isobars, as well as the electromagnetic $N-\Delta$ transition form factors are studied systematically and continuously using a covariant quark-diquark approach…
The electromagnetic excitation of the nucleon resonances is studied in the framework of Constituent Quark Models. Particular attention is devoted to the transition to the $\Delta$ resonance and to the issue of a possible deformation of…
In treating the relativistic three-quark problem, a dressed-quark propagator parameterization is used which is compatible with recent lattice data and pion observables. Furthermore two-quark correlations are modeled as a series of quark…
The electromagnetic and axial form factors of the nucleon and its lowest positive parity excitations, the Delta(1232) and the N*(1440), are calculated with constituent-quark models that are specified by simple algebraic representations of…
We calculate electromagnetic form factors of the proton bound in specified orbits for several closed shell nuclei. The quark structure of the nucleon and the shell structure of the finite nuclei are given by the QMC model. We find that…
The electromagnetic form factors of the nucleon, in the space-like region, are determined from three-point function Finite Energy QCD Sum Rules. The QCD calculation is performed to leading order in perturbation theory in the chiral limit,…
The electromagnetic form factors are the most fundamental quantities to describe the internal structure of the nucleon and the shape of a spatially extended particle is determined by its intrinsic quadrupole moment which can be related to…
We calculate the electromagnetic form factors of a bound proton. The Chiral Quark-Soliton model provides the quark and antiquark substructure of the proton, which is embedded in nuclear matter. This procedure yields significant…
The neutron charge form factor $G_{En}(q)$ is determined from an analysis of the deuteron quadrupole form factor $F_{C2}$ data. Recent calculations, based on a variety of different model interactions and currents, indicate that the…
We calculate the axial $N\to \Delta(1232)$ and $N\to N^{\star}(1440)$ transition form factors in a chiral constituent quark model. As required by the partial conservation of axial current ($PCAC$) condition, we include one- and two-body…