Flavor content of nucleon form factors in a VMD approach
نویسنده
چکیده
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 and G0 collaborations shows a good overall agreement. It is shown that the strangeness contribution to the electric and magnetic form factors is of the order of a few percent. In particular, the strange quark contribution to the charge radius is small 〈
منابع مشابه
Origin of the Nucleon Electromagnetic Form Factors Dipole Formula
Starting with the VMD parametrization of the electric and magnetic nucleon form factors, which are saturated just by the ground state vector-mesons ρ, ω and φ, then aplying the strict OZI rule and the asymptotic behaviour of form factors as predicted by quark model of hadrons, the famous one parameter dipole formula is derived. By its comparison with space-like data up to t = −5 GeV 2 the most ...
متن کاملElectromagnetic form factors in a collective model of the nucleon.
We study the electromagnetic form factors of the nucleon in a collective model of baryons. Using the algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electroand photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing ...
متن کاملFlavor Decomposition of the Nucleon A
I review some recent developments in the study of quark flavor distributions in the nucleon, including (i) valence quark distributions and the quark–hadron duality prediction for the x → 1 d/u ratio (ii) sea quark asymmetries and electromagnetic form factors (iii) strange quarks in the nucleon.
متن کاملProbing Proton Strangeness with Time-Like Virtual Compton Scattering
We document that p(γ, e+e−)p measurements will yield new, important information about the off-shell time-like nucleon form factors, especially in the φ meson region (q2 = M2 φ) governing the φN couplings g V,T φNN . Calculations for p(γ, e +e−)p, utilizing vector meson dominance, predict measurable φ enhancements at high |t| compared to the expected φ background production from π, η and Pomeron...
متن کاملJust How Strange? Loops, Poles and the Strangeness Radius of the Nucleon
We consider a simple model for the strangeness radius of the nucleon. The model is based on vector meson dominance (VMD) and ω − φ mixing in addition to a kaon cloud contribution. We find that the VMD contribution is similar in magnitude and of the same sign as the kaon contribution to the Sachs strangeness radius and is significantly larger than the kaon contribution to the Dirac radius.
متن کامل