93 research outputs found
Unitary and analytic model of nucleon EM structure, the puzzle with JLab proton polarization data and new insight into proton charge distribution
The Unitary and analytic model of nucleon electromagnetic structure,
describing all existing nucleon form factor data, is briefly reviewed. Then in
the framework of this model the problem of inconsistency of older proton
electric form factor data in space-like region (obtained from process by the Rosenbluth technique) with recent Jefferson Lab data on
the ratio (measured in precise polarization
experiment) is suggested
to be solved in favour of the latter data which, however, unlike older data
cause an existence of the form factor zero, i.e. a difraction minimum in
around GeV. The new behaviour of
with the zero gives modified proton charge distribution with enlarged value of
the mean square charge radius.Comment: 9 pages, 11 eps figures. Talk presented at the workshop on Lepton
Scattering and the Structure of Hadrons and Nuclei, Erice (Italy), September
200
Manifestation of the JLab proton polarization data on the behaviour of strange nucleon form factors
Special eight-resonance unitary and analytic model of nucleon electromagnetic
structure is used to analyze, first the classical proton form factor data
obtained by the Rosenbluth technique and then also the contradicting JLab
proton polarization data on the ratio with the
aim to investigate a manifestation of the latter on the strange nucleon form
factors behaviour.Comment: Latex, 9 pages, 3 figures. Talk given at the PAVI06 International
Workshop, 16-20 May, 2006, Milos, Greec
New sum rules for nucleon and trinucleon total photoproduction cross-sections
Two new sum rules are derived relating Dirac radii and anomalous magnetic
moments of the considered strongly interacting fermions with the convergent
integral over a difference of the total proton and neutron, as well as
and , photoproduction cross-sections.Comment: 1 eps figure. Contribution presented at the PHOTON'03, April 7-11,
2003, Frascati (Roma), Ital
Sum rule for a difference of proton and neutron total photoproduction cross-sections
Starting from very high energy inelastic electron-nucleon scattering with a
production of a hadronic state to be moved closely to the direction of the
initial nucleon, then utilizing analytic properties of parts of forward virtual
Compton scattering amplitudes on proton and neutron, one obtains the relation
between nucleon form factors and a difference of proton and neutron
differential electroproduction cross-sections. In particular, for the case of
small transferred momenta, one finally derives sum rule, relating Dirac proton
mean square radius and anomalous magnetic moments of proton and neutron to the
integral over a difference of the total proton and neutron photoproduction
cross-sections.Comment: LaTeX2e, 7 pages, 1 eps figure (revised version
Polarizacijski podaci za protone iz JLaba i globalni unitarni i analitiÄki model EM strukture nukleona
It is demonstrated that the new JLab proton polarization data, which are in a rather strong disagreement with the proton electric form factor data in the space-like region obtained by the Rosenbluth technique, are consistent with all known form factor properties, including also the QCD asymptotics. However, they require the existence of a zero value (i.e. a diffraction minimum) of the proton electric form factor around t=15 GeV2. That leads to a change of our understanding of the charge distribution inside the proton.Pokazujemo da novi polarizacijski podaci iz JLaba za protone, koji su u velikom neskladu s podacima za protonski elektriÄni faktor oblika u prostornom podruÄju izvedenim Rosenbluthovom metodom, su u skladu sa svim poznatim svojstvima faktora oblika, ukljuÄivÅ”i i QCD asimptotiÄke vrijednosti. MeÄutim, oni zahtijevaju nultu vrijednost (tj., difrakcijski minimum) protonskog elektriÄnog faktora oblika oko t=15 GeV2 . To mijenja naÅ”e poznavanje raspodjele naboja u protonu
Prediction of neutron electromagnetic form factors behaviors just by the proton electromagnetic form factors data
It is demonstrated how the neutron electromagnetic form factors behaviors in
the whole region of their definition can be predicted theoretically just by
using the proton form factors data to be described by the advanced proton
electromagnetic structure Unitary and Analytic model.Comment: 12 pages,8 figure
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