Related papers: Nucleon Excitations
The mass spectrum of Delta resonances is compared to predictions based on three quark-model variants, to predictions assuming that chiral symmetry is restored in high-mass baryon resonances, and to predictions derived from AdS/QCD. The…
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…
The 1/N expansion of QCD can be used to calculate properties of nucleons and Delta baryons, such as masses, magnetic moments, and pion couplings. The predictions of the 1/N expansion are in excellent agreement with the experimental data.…
The mass spectra of nucleon resonances with spin 1/2, 3/2, and 5/2 are systematically studied in the constituent quark model with meson-quark coupling, which is inspired by the spontaneous breaking of chiral symmetry of QCD. The meson-quark…
Partial restoration in nuclear matter of the chiral symmetry of QCD is discussed together with some of its possible signals. Estimates of corrections to the leading, linear dependence of the quark condensate are found to be small, implying…
The role of the quark condensate in low-energy QCD and its behaviour in nuclear matter are discussed. Partial restoration of chiral symmetry, as indicated by a reduction of the quark condensate in matter, could significantly alter the…
We discuss the relevance of the scalar modes appearing in chiral theories with spontaneous symmetry breaking such as the NJL model for nuclear matter studies. We show that it depends on the relative role of chiral symmetry breaking and…
I discuss developments in the area of nucleon resonance excitations that are necessary to bring our understanding of nucleon structure in the regime of strong QCD to a qualitatively new level. They involve the collection of high quality…
We look for $\Delta\Delta$ and $N\Delta$ resonances by calculating $NN$ scattering phase shifts of two interacting baryon clusters of quarks with explicit coupling to these dibaryon channels. Two phenomenological nonrelativistic chiral…
We review the chiral variant and invariant components of nucleon masses and its consequence on the chiral restoration in extreme conditions, neutron star matter in particular. We consider a model of linear realization of chiral symmetry…
We discuss the mass spectrum of highly-excited nucleon and $\Delta^*$ resonances. The spectrum exhibits parity doublets, pairs of resonances of identical total angular momentum J but of opposite parity. It has been proposed that the parity…
The development of a dynamical model for investigating the nucleon resonances using the reactions of meson production from \pi N, \gamma N, N(e,e'), and N(\nu,{\it l}) reactions is reviewed. The results for the \Delta (1232) state are…
We compare axial charges of excited nucleons, as predicted by the chiral symmetry restoration picture, with the traditional, moderately successful for the ground-state baryons SU(6) symmetry. The axial charges of excited nucleons can (and…
The lower excitation spectrum of the nucleon and $\Delta$ is calculated in a relativistic chiral quark model. Contributions of the second order self-energy and exchange diagrams due-to pion fields to the mass spectrum of the SU(2) baryons…
Understanding hadron structure within the framework of QCD is an extremely challenging problem. In order to solve it, it is vital that our thinking should be guided by the best available insight. Our purpose here is to explain the model…
We study a chiral relativistic theory of nuclear matter aimed at the desciption of both the binding and saturation properties and the QCD properties, quark condensate and QCD susceptibilities. For this purpose the nucleon scalar response of…
The SU(2) Skyrme model is reviewed. The model, which considers hadron as soliton (Skyrmion), is used for investigating the nucleon mass and delta mass. Keywords: Skyrme model, soliton, hadron, nucleon mass, delta mass.
In this talk we present a description of nuclear binding in a chiral approach based on the existence of a chiral invariant scalar field associated with the generation of the masses through spontaneous chiral symmetry breaking. We discuss…
We present a theoretical framework allowing to make an explicit connection between the phenomenology of QCD, namely the properties of the gluon correlator and Wilson loops, and a particular relativistic model for the description of nuclear…
We discuss the sensitivity of nucleon properties (mass, magnetic moments and electromagnetic form factors) on the variation of the pseudoscalar meson masses in the context of the perturbative chiral quark model. The obtained results are…