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Few-Body Systems

, 60:13 | Cite as

Constituent-Quark Model with Pionic Contributions: Electromagnetic \({\varvec{N\rightarrow \varDelta }}\) Transition

  • Ju-Hyun Jung
  • Wolfgang SchweigerEmail author
  • Elmar P. Biernat
Open Access
Article
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Part of the following topical collections:
  1. NSTAR 2017

Abstract

We report on ongoing work to determine the pion-cloud contribution to the electromagnetic \(N\rightarrow \varDelta \) transition form factors. The starting point is an SU(6) spin-flavor symmetric constituent-quark model with instantaneous confinement that is augmented by dynamical pions which couple directly to the quarks. This system is treated in a relativistically invariant way within the framework of point-form quantum mechanics using a multichannel formulation. The first step is to determine the electromagnetic form factors of the bare particles that consist only of three quarks. These form factors are basic ingredients for calculating the pion-cloud contributions. Already without the pion cloud, electromagnetic nucleon and \(N\rightarrow \varDelta \) transition form factors compare reasonably well with the data. By inclusion of the pion-cloud contribution coming from the \(\pi -N\) intermediate state the reproduction of the data is further improved.

Notes

Acknowledgments

J.-H. Jung acknowledges the support of the Fonds zur Förderung der wissenschaftlichen Forschung in Österreich (Grant No. FWF DK W1203-N16). He furthermore wants to thank Prof. T. Peña for giving him the opportunity to stay at the Centro de Física Teórica de Partículas, IST Lisboa, where part of this work was done. E. P. Biernat acknowledges the support of the Fundação para a Ciência e a Tecnologia (FCT) under Grant No. SFRH/BPD/100578/2014.

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© The Author(s) 2018

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Institut für Physik, FB Theoretische PhysikUniversität GrazGrazAustria
  2. 2.CFTP, Instituto Superior TécnicoUniversidade de LisboaLisboaPortugal

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