79 research outputs found
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
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
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
Faktori oblika pseudoskalarnih mezona od vektorske struje stranih kvarkova
Similarly to the electromagnetic pseudoscalar-meson transition form factors, one can also define strange-quark vector current pseudoscalar-meson transition form factors, contributing only to the behaviour of the isoscalar parts of the former ones. Their explicit form is found by constructing unitary and analytical models of the strange pseudoscalar-meson transition form factors dependent only on Ļ and Ļ coupling constant ratios as free parameters. Numerical values of these ratios are then determined from the corresponding pseudoscalar-meson transition form factors by employing the Ļ-Ļ mixing and a special assumption on the coupling of the quark components of vector-meson wave functions to the flavour component of currents under consideration.Poput elektromagnetskih prijelaznih faktora oblika pseudoskalarnih mezona, mogu se definirati i prijelazni faktori oblika pseudoskalarnih mezona od vektorske struje stranih kvarkova, koji doprinose samo svojstvima izoskalarnih dijelova prvih. Njihova se eksplicitna formulacija nalazi razvijanjem unitarnih i analitiÄkih modela za strane prijelazne faktore oblika pseudoskalarnih mezona koji ovise samo o omjerima konstanti vezanja Ļ and Ļ mezona kao slobodnim parametrima. Iznosi tih omjera se odreÄuju iz odnosnih prijelaznih faktora oblika pseudoskalarnih mezona upotrebom posebnog mijeÅ”anja Ļ-Ļ i posebnom pretpostavkom o vezanju kvarkovskih komponenata valnih funkcija vektorskih mezona na okusnu komponentu studiranih struja
Study of decays in covariant quark model
We study the rare radiative leptonic decays
() within the Standard Model, considering both the
structure-dependent amplitude and bremsstrahlung. In the framework of the
covariant confined quark model developed by us, we calculate the form factors
characterizing the transition in the full kinematical region of
the dilepton momentum squared and discuss their behavior. We provide the
analytic formula for the differential decay distribution and give predictions
for the branching fractions in both cases: with and without long-distance
contributions. Finally, we compare our results with those obtained in other
approaches.Comment: 22 pages, 8 figures, 6 tables, more references and material added, a
version to appear on PR
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