Magnetization screening from gluonic currents and scaling law violation in the ratio of magnetic form factors for neutron and proton

Abstract

The ratio ${\mu }_p{G}_E^p/G_M^p$ exhibits a decrease for four-momentum transfer Q^2 increasing beyond 1 GeV^2 indicating different spatial distributions for charge and for magnetization inside the proton. One-gluon exchange currents can explain this behaviour. The SU(6) breaking induced by gluonic currents predicts furthermore that the ratio of neutron to proton magnetic form factors ${\mu }_p{G}_M^n/{\mu }_n{G}_M^p$ falls with increasing Q^2. We find that the experimental data are consistent with our expectations of an almost linear decrease of the ratio ${\mu }_p{G}_M^n/{\mu }_n{G}_M^p$ with increasing Q^2, supporting the statement that the spatial distributions of magnetization are different for protons and for neutrons.

10 pages, 3 figures

References in corpus (10)

• Two-photon exchange and elastic electron-proton scattering
• How to reconcile the Rosenbluth and the polarization transfer method in the measurement of the proton form factors
• A Coherent Interpretation of the Form Factors of the Nucleon in Terms of a Pion Cloud and Constituent Quarks
• Perturbative QCD Analysis of the Nucleon's Pauli Form Factor F_2(Q^2)
• How well do we know the electromagnetic form factors of the proton?
• Measurements of GEn/GMn from the ^2H(vec{e},e'vec{n})^1H Reaction to Q^2=1.45 (GeV/c)^2
• Status on nucleon electromagnetic form factors
• Shapes of the Proton
• A dressed bag model study of the final-state $N\Delta$ interaction in photoproduction processes off the deuteron
• Effect of gluon-exchange pair-currents on the ratio G(E(P))/G(M(P))

Cited by in corpus (4)

• Measurements of the neutron electric to magnetic form factor ratio GEn/GMn via the ^2H(\vec{e},e'\vec{n})^1H reaction to Q^2 = 1.45 (GeV/c)^2
• Deep exclusive charged $\pi$ electroproduction above the resonance region
• Correlated two-pion exchange and large-N(C) behavior of nuclear forces
• Primakoff production of ${\pi }^0$, $\eta$ and ${\eta }^{\prime }$ in the Coulomb field of a nucleus