A consistent dynamical model for pion-photoproduction

Pion-photoproduction amplitude is calculated within a consistent isobar model already used to fix the Δ+ + (1232   MeV) parameters in pion-nucleon scattering and bremsstrahlung. This amplitude is expressed in terms of (physical) on-shell quantities and off-shell contributions coming from final state...

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Autor principal: Mariano, Alejandro Edgardo
Formato: Articulo
Lenguaje:Inglés
Publicado: 2007
Materias:
Física
Pion-photoproduction
isobar model
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/82981
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-82981
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Física
Pion-photoproduction
isobar model
spellingShingle Física
Pion-photoproduction
isobar model
Mariano, Alejandro Edgardo
A consistent dynamical model for pion-photoproduction
topic_facet Física
Pion-photoproduction
isobar model
description Pion-photoproduction amplitude is calculated within a consistent isobar model already used to fix the Δ+ + (1232   MeV) parameters in pion-nucleon scattering and bremsstrahlung. This amplitude is expressed in terms of (physical) on-shell quantities and off-shell contributions coming from final state interactions. These latter are isolated in principal value integrals on the non-polar part of the pion-nucleon K-matrix, being the main effect of them to dress the bare form factors present in the γ N → Δ vertex. First, we hide the dressing into effective form factors getting at kγ2 = 0, GM = 2.97 ± 0.08 and GE = 0.055 ± 0.010 in full consistence with recent chiral effective field theory calculations. Then, different models to regularize the mentioned integrals are analyzed. We choose those better describing the non-resonant multipoles, in order to get model independent results for the resonant ones. Finally, we try to predict the bare form factors getting GM0 = 1.69 ± 0.02 and GE0 = 0.028 ± 0.008, which are consistent with recent lattice quark calculations and other more sophisticated dynamical models.
format Articulo
Articulo
author Mariano, Alejandro Edgardo
author_facet Mariano, Alejandro Edgardo
author_sort Mariano, Alejandro Edgardo
title A consistent dynamical model for pion-photoproduction
title_short A consistent dynamical model for pion-photoproduction
title_full A consistent dynamical model for pion-photoproduction
title_fullStr A consistent dynamical model for pion-photoproduction
title_full_unstemmed A consistent dynamical model for pion-photoproduction
title_sort consistent dynamical model for pion-photoproduction
publishDate 2007
url http://sedici.unlp.edu.ar/handle/10915/82981
work_keys_str_mv AT marianoalejandroedgardo aconsistentdynamicalmodelforpionphotoproduction
AT marianoalejandroedgardo consistentdynamicalmodelforpionphotoproduction
bdutipo_str Repositorios
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