Electroweak structure of the nucleon, meson cloud and light-cone wavefunctions

Abstract

The meson-cloud model of the nucleon consisting of a system of three valence quarks surrounded by a meson cloud is applied to study the electroweak structure of the proton and neutron. Light-cone wavefunctions are derived for the dressed nucleon as pictured to be part of the time a bare nucleon and part of the time a baryon-meson system. Configurations are considered where the baryon can be a nucleon or a Δand the meson can be a pion as well as a vector meson such as the ρor the ω. An overall good description of the electroweak form factors is obtained. The contribution of the meson cloud is small and only significant at low Q^2. Mixed-symmetry S'-wave components in the wavefunction are most important to reproduce the neutron electric form factor. Charge and magnetization densities are deduced as a function of both the radial distance from the nucleon center and the transverse distance with respect to the direction of the three-momentum transfer. In the latter case a central negative charge is found for the neutron. The up and down quark distributions associated with the Fourier transform of the axial form factor have opposite sign, with the consequence that the probability to find an up (down) quark with positive helicity is maximal when it is (anti)aligned with the proton helicity.

references updated and typos in figure 2 corrected; to be published in Phys. Rev. D

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• The quark orbital angular momentum from Wigner distributions and light-cone wave functions
• The Spin Structure of the Nucleon
• Azimuthal spin asymmetries in light-cone constituent quark models
• The Charge Form Factor of the Neutron at Low Momentum Transfer from the ${}^2\vec{\mathrm{H}}(\vec{\mathrm{e}},{\mathrm{e}}^{\prime }\mathrm{n})\mathrm{p}$ Reaction
• Periodic interference structures in the time-like proton form factor
• Sivers and Boer-Mulders functions in Light-Cone Quark Models
• Nucleon structure from basis light-front quantization
• Pion TMDs in light-front constituent approach, and Boer-Mulders effect in the pion-induced Drell-Yan process
• Analysis of nucleon electromagnetic form factors from light-front holographic QCD : The spacelike region
• Proton structure from a light-front Hamiltonian
• Naive time-reversal odd phenomena in semi-inclusive deep-inelastic scattering from light-cone constituent quark models
• Hadron structure at low Q^2
• Extracting many-body color charge correlators in the proton from exclusive DIS at large Bjorken x
• Color charge correlations in the proton at NLO: beyond geometry based intuition
• Multi-quark matrix elements in the proton and three gluon exchange for exclusive ${\eta }_c$ production in photon-proton diffractive scattering
• Axial charges of octet and decuplet baryons
• Helicity-dependent generalized parton distributions for nonzero skewness
• The Role of Mesons in the Electromagnetic Form Factors of the Nucleon
• Parton content of the nucleon from distribution amplitudes and transition distribution amplitudes
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• Axial form factors of the octet baryons in a covariant quark model
• Proton Electromagnetic Form Factor Ratios at Low Q^2
• Sub-femtometer scale color charge correlations in the proton
• The spin structure of the nucleon in light-cone quark models
• Collinear parton distributions and the structure of the nucleon sea in a light-front meson-cloud model
• Holographic estimate of the meson cloud contribution to nucleon axial form factor
• Unified model of nucleon elastic form factors and implications for neutrino-oscillation experiments
• Wigner distributions and quark orbital angular momentum
• Probing the parton content of the nucleon
• Weak interaction axial form factors of the octet baryons in nuclear medium
• Meson-cloud effects in the electromagnetic nucleon structure
• Nucleon Structure from Basis Light-Front Quantization : Status and Prospects
• The Pion-Cloud Contribution to the Electromagnetic Nucleon Form Factors
• On the microscopic structure of $\pi NN$, $\pi N\Delta$ and $\pi \Delta \Delta$ vertices
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