Related papers: Nucleon Resonances and Quark Structure
An explicit quark model, based on a mean field description of non-overlapping nucleon bags bound by the self-consistent exchange of $\sigma$, $\omega$ and $\rho$ mesons, is used to investigate the properties of both nuclear and neutron…
I review recent lattice results on the spectrum and structure of baryons. Limitations due to the quenched approximation and un-physically heavy up and down quarks are discussed, and interfaces between first principles studies of QCD (or…
We show that the boundary between quark-dominated and hadron-dominated regions of nuclear structure may be blurred by multi-nucleon quark clusters arising from color percolation. Recent experiments supporting partial percolation in cold…
We study the behavior of dynamically-generated baryon resonances with heavy-quark content within a unitarized coupled-channel theory in matter that fulfills heavy-quark spin symmetry constraints. We analyze the implications for the…
For a long time people made the mistake of thinking the proton was understood. New experiments, ranging from form factors to deeply virtual Compton scattering, promise a new era of highly informative studies. Among the controversial topics…
Concepts of wounded nucleon and quark participants have been used for years to parametrize and/or to explain many features of high energy nuclear collisions. Some results illustrating successes and failures of these two approaches are…
Several topics concerning nuclear structure and electromagnetic interactions of heavy nuclei are reviewed. These comprehend the deformed single-particle shell model, nuclear collective motion, symmetry breaking and approximate symmetry…
Nucleon electromagnetic form factors are fundamental quantities related to the charge and magnetization distributions inside the nucleon. Understanding the nucleon electromagnetic structure in terms of the underlying quark and gluon degrees…
We explore the role of a scalar meson exchange interaction between quarks in a semirelativistic constituent quark model where the quarks are also subject to a linear confinement. We search for a variational solution and study how the…
We present a review of the state-of-the-art of our understanding of the intrinsic charm and bottom content of the nucleon. We discuss theoretical calculations, constraints from global analyses, and collider observables sensitive to the…
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…
In this talk, I discuss some recent results obtained in Heavy Ion Collisions and what they tell us -- or what questions they raise -- about the physics of the system of quarks and gluons formed in these collisions.
Using a geometric model for the study of the structure of hadrons, we study baryons having one, two and three heavy quarks. The study reveals diquark structure in baryons with one and two heavy quarks but not with three heavy identical…
We explore the physics of the parton-hadron duality in the nucleon structure functions appearing in lepton-nucleon scattering. We stress that the duality allows one to extract the higher-twist matrix elements from data in the resonance…
This PhD thesis is devoted to the low-energy structure of the nucleon (proton and neutron) as seen through electromagnetic probes, e.g., electron and Compton scattering. The research presented here is based primarily on dispersion theory…
A gauge invariant method for the investigation of scalar diquark clustering in the nucleon ground state is presented. The method focuses on a comparison of quark distributions in the nucleon with those in the $\Delta$ baryon resonance.…
In recent years the study of two particle systems on the lattice has led to excellent results in the meson sector of the QCD spectrum, however baryon resonances mostly remain unexplored. We present a study of pion-nucleon systems as decay…
Searches for new physics typically rely on proton-proton collisions, where isolated mass bumps are the primary signatures. However, when a new particle is nearly degenerate in mass with a known Standard Model resonance, it can be partially…
We address an actual problem of baryon-resonance dominated meson-exchange processes in the low GeV regime, i.e. the phase and the structure of meson-NN* transition vertices. Our starting point is a quark-diquark model for the baryons…
The theory of nuclear excitations involving nucleon resonances is revisited and significantly extended to asymmetric nuclear matter and higher P- and S-wave $N^*$ resonances. Excited states of are described as superpositions of…