Related papers: Electromagnetic processes and the diquark model
Starting from the Fock space representation of hadron bound states in a quark model, a change of representation is implemented by a unitary transformation such that the composite hadrons are redescribed by elementary-particle field…
A constituent quark model based on the spectator formalism is applied to the gamma N -> N* transition for the three cases, where N* is the nucleon, the Delta and the Roper resonance. The model is covariant, and therefore can be used for the…
Nucleon electromagnetic form factors are studied in the cloudy bag model (CBM) with center-of-mass and recoil corrections. This is the first presentation of a full set of nucleon form factors using the CBM. The center of mass motion is…
Investigation of the spacelike and timelike electromagnetic form factors of hadrons, within a relativistic microscopical model characterized by a small set of hypothesis, could shed light on the components of hadron states beyond the…
The electromagnetic properties of baryons containing a heavy quark are calculated at next-to-leading order in partially quenched heavy hadron chiral perturbation theory. Calculations are performed for three light flavors in the isospin…
We discuss applications of the dispersion quark model to exclusive semileptonic decays of heavy mesons. The transition form factors in this relativistic formulation of the quark model are given by double spectral representations through the…
The parameter-free predictions for the $N - P_{11}(1440)$ and $N - P_{33}(1232)$ electromagnetic transition form factors, obtained within our light-front constituent quark model using eigenfunctions of a baryon mass operator which includes…
High-precision nucleon-resonance electroproduction data on a large kinematic domain of energy and momentum transfer have proven crucial in revealing novel features of strong interactions within the Standard Model and unfolding structural…
A family of simply solvable covariant quark models for the baryons is presented. With optimal parameter choices the models reproduce the empirical spectra of the baryons in all flavor sectors to an accuracy of a few percent. Complete…
Recent experimental and theoretical advancements have led to significant progress in our understanding of the electromagnetic structure of nucleons ($N$), nucleon excitations ($N^\ast$), and other baryons. These breakthroughs have been made…
In this contribution, we present the unquenched quark model as an extension of the constituent quark model that includes the effects of sea quarks via a $^{3}P_{0}$ quark-antiquark pair-creation mechanism. Particular attention is paid to…
Measurements of heavy quark production in electron-positron collisions are used to analyse the strong interactions between quarks and anti-quarks. A scaling behaviour is observed in distributions of the rapidity change of D*, B*, and B…
We apply a dynamical three-constituent quark light-front model to study the proton. The dynamics is based on the notion of a diquark (bound or virtual) as the dominant interaction channel, which paramaterizes a contact interaction between…
The electromagnetic form factors of the nucleon are calculated in an extended chiral constituent-quark model where the effective interaction is described by the exchange of pseudoscalar, vector, and scalar mesons. Two-body current-density…
Weak current-induced baryonic form factors at zero recoil are evaluated in the rest frame of the heavy parent baryon using the nonrelativistic quark model. Contrary to previous similar work in the literature, our quark model results do…
It is shown how the exchange interaction, the dipole-dipole interaction, and the Dzyaloshinsky-Moriya interaction between electronic spin-density fluctuations emerge naturally from a field-theoretic framework that couples electrons to the…
An overview of the latest theoretical developments and results on electromagnetic and weak probes in relativistic heavy-ion collisions is presented. The possibilities to use electromagnetic probes, i.e., photons and dileptons, as a…
We study the semileptonic decays of double heavy baryons using a manifestly Lorentz covariant constituent three-quark model. We present complete results on transition form factors between double-heavy baryons for finite values of the heavy…
We present a calculation of the electric and magnetic form factors of ground-state octet and decuplet baryons including strange quarks. We work with a combination of Dyson-Schwinger equations for the quark propagator and covariant…
We present comprehensive calculations of the electromagnetic form factors, including the charge, magnetic-dipole, electric-quadrupole and magnetic-octupole form factors, of the $\Omega^-$ in the spacelike region using the quark-diquark…