Related papers: Are There Diquarks in the Nucleon?
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 Poincar\'e-covariant Faddeev equation to…
Nucleon structure functions, as measured in deep-inelastic lepton scattering, are studied within a covariant scalar diquark spectator model. Regarding the nucleon as an approximate two-body bound state of a quark and diquark, the…
Measurement of the neutral weak vector form factors of the nucleon provides unique access to the strange quark content of the nucleon. These form factors can be studied using parity-violating electron scattering. A comprehensive program of…
The importance of diquarks has been noticed in the context of several elementary particle processes. In recent years the study of diquarks has become of considerable interest in highlighting its role in high density physics from the point…
A covariant, composite scalar diquark, Fadde'ev amplitude model for the nucleon is used to calculate pseudoscalar, isoscalar- and isovector-vector, axial-vector and scalar nucleon form factors. The last yields the nucleon sigma-term and…
A microscopic calculation of the equation of state for asymmetric nuclear matter is presented. We employ realistic nucleon-nucleon forces and operate within the Dirac-Brueckner-Hartree-Fock approach to nuclear matter. The focal point of…
We present arguments suggesting that large size overlapping instantons are the driving mechanism of the confinement-deconfinement phase transition at nonzero chemical potential mu. The arguments are based on the picture that instantons at…
Nucleon electromagnetic form factors are considered in the framework of the generalized Skyrme model with dilaton-quarkonium field. In our recent publication we have got big discrepancies between calculated form factors and dipole…
To obtain further information on the geometric shape of the nucleon, the proton charge form factor is decomposed into two terms, which are connected respectively with a spherically symmetric and an intrinsic quadrupole part of the proton's…
This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a…
A dressed-quark core contribution to nucleon electromagnetic form factors is calculated. It is defined by the solution of a Poincare' covariant Faddeev equation in which dressed-quarks provide the elementary degree of freedom and…
Following a recently proposed confinement generating mechanism, we provide a new string inspired model with a massive dilaton and a new dilaton coupling function [5]. By solving analytically the equations of motion, a new class of confining…
A simple quark-diquark model for nucleon and $\Lambda$ structure is used to calculate leading twist light-cone fragmentation functions for a quark to inclusively decay into P or $\Lambda$. The parameters of the model are determined by…
Spectrum of the low-lying hidden- and double-charm tetraquark states are investigated in a nonrelativistic quark potential model, where the Instanton-induced interaction is taken as the residual spin-dependent hyperfine interaction between…
A review of the underlying ideas of the Interacting Quark Diquark Model (IQDM) that asses the baryon spectroscopy in terms of quark diquark degrees of freedom is given, together with a discussion of the missing resonances problem. Some…
We describe aspects of the role that diquark correlations play in understanding baryon structure and interactions. The significance of diquarks in that application motivates a study of the possibility that dense hadronic matter may exhibit…
Hexaquarks constitute a natural extension of complex quark systems like also tetra- and pentaquarks do. To this end the current status of $d^*(2380)$ in both experiment and theory is shortly reviewed. Recent high-precision measurements in…
We evaluate a number of new instanton-induced phenomena in QCD, starting with static dipole-dipole potentials, and proceeding to quark-quark and dipole-dipole scattering at high energy. We use a non-perturbative formulation of the…
The relativistic structure of the self-energy of a nucleon in nuclear matter is investigated including the imaginary and real components which arise from the terms of first and second order in the NN interaction. A parameterized form of…
The electromagnetic form factors of the proton and the neutron in the timelike region are reviewed. In view of the forthcoming experimental projects devoted to investigate these observables, we present the current status of the field and we…