Related papers: Electroweak structure of the nucleon, meson cloud …
The momentum distributions of the constituent quarks inside the nucleon and the prominent electroproduced nucleon resonances are investigated in the two most sophisticated, available quark potential models, based respectively on the…
We produce the light-front wave functions (LFWFs) of the nucleon from a basis light-front ap- proach in the leading Fock sector representation. We solve for the mass eigenstates from a light-front effective Hamiltonian, which includes a…
The momentum distributions of pions and $\rho$-mesons in the nucleon are extracted from experiment. Perspectives of the quark microscopic theory of mesonic cloud are outlined.
The recent unbiased measurements of the electric form factor of the neutron suggest that its shape may be interpreted as a smooth broad distribution with a bump at Q^2 \approx 0.3(GeV/c)^2 superimposed. As a consequence the corresponding…
The kaon electromagnetic (e.m.) form factor is reviewed considering a light-front constituent quark model. In this approach, it is discussed the relevance of the quark-antiquark pair terms for the full covariance of the e.m. current. It is…
A detailed study of nucleon parton distribution functions is performed within a radiative Next-to-Next-to Leading Order (NNLO) parton model whose low-scale input is rigidly described by wave functions which include quarks and dressing…
Nucleon and pion electromagnetic form factors are evaluated in the spacelike region within a light-front constituent quark model, where eigenfunctions of a mass operator, reproducing a large set of hadron energy levels, are adopted and…
In the present work we study the effect of the scalar spin coupling of constituent quarks on the nucleon electroweak properties by introducing a valence light-front wave function with two momentum scales. By comparing the results obtained…
We compute electroweak form factors of the nucleon and photon transition form factors of non-strange baryon resonances up to the third resonance region in a model with instanton-induced interaction. The calculation is based on the…
The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX…
We present a general formalism that uses the point form of relativistic Hamiltonian dynamics to describe the electroweak structure of heavy-light mesons within constituent quark models. We study the heavy quark limit (i.e. $m_Q\to \infty$)…
Current light-cone wave functions for the nucleon are unsatisfactory since they are in conflict with the data of the nucleon's Dirac form factor at large momentum transfer. Therefore, we attempt a determination of a new wave function…
We investigate the imaginary parts of the nucleon electromagnetic and axial form factors close to threshold in the framework of heavy baryon chiral perturbation theory. For the isovector electromagnetic form factors, we recover the well…
We present selected results from a calculation of meson and nucleon observables in a Green-function approach. A rainbow-ladder truncation of QCD's Dyson-Schwinger equations is used to solve the respective meson, diquark and quark-diquark…
The strangeness content of nucleon form factors is analyzed in a two-component model with a quark-like intrinsic structure surrounded by a meson cloud. A comparison with the available experimental data from the SAMPLE, PVA4, HAPPEX and G0…
Recent experimental data on space-like and time-like form factors of the nucleon are reviewed in light of a model of the nucleon with an intrinsic (quark-like) structure and a meson cloud. The analysis points to the astonishing result that…
We have developed a physical model for the non-perturbative x-shape of parton density functions in the proton, based on Gaussian fluctuations in momenta, and quantum fluctuations of the proton into meson-baryon pairs. The model describes…
The present contribution continues and extends foregoing work on the calculation of electroweak form factors of hadrons using the point-form of relativistic quantum mechanics. Here we are particularly interested in studying pionic effects…
The phenomenological sum-rule-based approach is used to discuss the quark composition dependence of some static and quasi-static electroweak characteristics of nucleons.The role of nonvalence degrees of freedom, the nucleon sea partons…
We study the response of the nucleon, as a system of three bound (constituent) non relativistic quarks, to external (quasi static) electric and magnetic fields. The approach, based on a sum rule technique, is applied to a large class of two…