English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We analyzed the presently available experimental data on nucleonelectromagnetic form factors within a multipole model based on dispersionrelations. A good fit of the data is achieved by considering the coefficientsof the multipole expansions as logarithmic functions of the momentum transfersquared. The superconvergence relations, applied to this coefficients, makesthe model agree with unitary constraints and pQCD asymptotics for the Dirac andPauli form factors. The soft photon emission is proposed as a mechanismresponsible for the difference between the Rosenbluth, polarization andbeam--target--asymmetry data. It is shown, that the experimentally measuredcross sections depend not only on the Dirac and Pauli form factors, but also onthe average number of the photons emitted. For proton this number is shown tobe different for different types of experimental measurements and thenestimated phenomenologically. For neutron the same mechanism predicts, that thedata form different types of experiments must coincide with high accuracy. Ajoint fit of all the experimental data reproduce the $Q^2-$dependence with theaccuracy $\chi^2/dof=0.86$. Predictions of the model, that 1) the ratios of theproton form factors $G_E/G_M$ are different for Rosenbluth, polarization andbeam--target--asymmetry experiments and 2) similar ratios are nearly the samefor neutron, can be used for experimental verification of the model.

Logarithmic corrections and soft photon phenomenology in the multipole model of the nucleon form factors