Related papers: Meson Clouds and Nucleon Electromagnetic Form Fact…
We calculate the corrections to the strange matrix elements of the nucleon resulting from the breaking of rotational invariance on the light-cone. In the meson cloud model, the strange magnetic moment mu_S is seen to change sign once the…
I review the results of a recent dispersion--theoretical analysis of the nucleon electromagnetic form factors and comment on the strangeness form factors. The need for a better data basis at low, intermediate and large momentum transfer is…
We obtain the electromagnetic form factors, the axial form factor, and the parton distribution functions of the proton from the eigenstates of a light-front effective Hamiltonian in the leading Fock representation suitable for low-momentum…
A review of neutron form factor measurements is given. We focus on recent measurements of the neutron magnetic form factor $G_M^n$, and discuss in detail our measurements of this quantity at momentum transfers Q^2=0.1-0.6 (GeV/c)^2.
To know and understand form factors of hadronic currents is of decisive importance for analysing exclusive weak decays. The ratios of different form factors of a given process depend on the relativistic spin structure of initial and final…
Meson decays are considered within the constituent quark model, making use of the dispersion formulation of the model: Starting with spacelike momentum transfers $q$, meson transition form factors are expressed as relativistic invariant…
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…
Electromagnetic form factors of a massive neutrino are studied in a minimally extended standard model in an arbitrary $R_{\xi}$ gauge and taking into account the dependence on the masses of all interacting particles. The contribution from…
Based on the recent, high precision data for elastic electron scattering from protons and deuterons, at relatively large momentum transfer $Q^2$, we determine the neutron electric form factor up to $Q^2=3.5$ GeV$^2$. The values obtained…
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…
The chiral quark model describes the strangeness components of the light quarks as fluctuations into strange mesons and quarks. The single strange pseudoscalar and vector meson loop fluctuations of the constituent $u$- and $d$-quarks give…
We investigate the effects of mesonic clouds on neutron electric and nucleon strange form factors in the framework of the chiral quark soliton model. We present a mechanism to identify the mesonic clouds and their Yukawa tail in the…
The first moment of longitudinal and transverse spin densities of quarks in the nucleon are calculated in a light-front constituent quark model for the different cases of quark and nucleon polarization. Significant distortions are found for…
The electromagnetic and gravitational form factors of the nucleon determined by quark and gluon contributions are calculated using the momentum transfer dependence of generalized parton distributions with different forms of parton…
We discuss the recent interpretation of quark-distribution functions in the plane transverse to the light-cone direction. Such a mapping is model independent and allows one to build up multidimensional pictures of the hadron and to develop…
Models of generalized parton distributions at zero skewness are used to relate the behavior of deep inelastic scattering quark distributions, evaluated at high x, to the transverse charge density evaluated at small distances. We obtain an…
We discuss two descriptions of the nucleon's strange vector form factors in the framework of vector meson dominance. The first, an updated and extended version of Jaffe's dispersion analysis, approximates the spectral functions of the form…
The electromagnetic form factors provide important hints for the internal structure of the nucleon and continue to be of major interest for experimentalists. For an intermediate range of momentum transfers the form factors can be calculated…
The role of the strange quarks on the low-energy interactions of the proton can be probed through the strange electromagnetic form factors. Knowledge of these form factors provides essential input for parity-violating processes and…
Elastic electromagnetic form factors of nucleons are investigated both for the time-like and the space-like momentums by using the unsubtracted dispersion relation with QCD constraints. It is shown that the calculated form factors reproduce…