# $$N^*$$ N ∗ form Factors Based on a Covariant Quark Model

$$N^*$$ N ∗ form Factors Based on a Covariant Quark Model We discuss the results of the covariant spectator quark model for the several $$\gamma ^*N \rightarrow N^*$$ γ ∗ N → N ∗ transitions, where N is the nucleon and $$N^*$$ N ∗ a nucleon excitation. More specifically, we present predictions for the form factors and transition amplitudes associated with the resonances $$N(1440)1/2^+$$ N ( 1440 ) 1 / 2 + , $$N(1535)1/2^-$$ N ( 1535 ) 1 / 2 - , $$N(1520)3/2^-$$ N ( 1520 ) 3 / 2 - , $$\varDelta (1620)1/2^-$$ Δ ( 1620 ) 1 / 2 - and $$N(1650)1/2^-$$ N ( 1650 ) 1 / 2 - . The estimates based on valence quark degrees of freedom are compared with the available data, particularly with the recent Jefferson Lab data at low and large momentum transfer ( $$Q^2$$ Q 2 ). In general the estimates are in good agreement with the empirical data for $$Q^2 >2$$ Q 2 > 2 GeV $$^2$$ 2 , with a few exceptions. The results are discussed in terms of the role of the valence quarks and the meson cloud excitations for the different resonances $$N^*$$ N ∗ . We also review our results for the resonance $$\varDelta (1232)3/2^+$$ Δ ( 1232 ) 3 / 2 + and discuss the relevance of the pion cloud component for the magnetic dipole form factor and the electric and Coulomb quadrupole form factors. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Few-Body Systems Springer Journals

# $$N^*$$ N ∗ form Factors Based on a Covariant Quark Model

, Volume 59 (5) – Jun 4, 2018
20 pages

/lp/springer_journal/n-n-form-factors-based-on-a-covariant-quark-model-vV8i1drtUv
Publisher
Springer Journals
Copyright © 2018 by Springer-Verlag GmbH Austria, part of Springer Nature
Subject
Physics; Particle and Nuclear Physics; Nuclear Physics, Heavy Ions, Hadrons; Atomic, Molecular, Optical and Plasma Physics
ISSN
0177-7963
eISSN
1432-5411
D.O.I.
10.1007/s00601-018-1412-9
Publisher site
See Article on Publisher Site

### Abstract

We discuss the results of the covariant spectator quark model for the several $$\gamma ^*N \rightarrow N^*$$ γ ∗ N → N ∗ transitions, where N is the nucleon and $$N^*$$ N ∗ a nucleon excitation. More specifically, we present predictions for the form factors and transition amplitudes associated with the resonances $$N(1440)1/2^+$$ N ( 1440 ) 1 / 2 + , $$N(1535)1/2^-$$ N ( 1535 ) 1 / 2 - , $$N(1520)3/2^-$$ N ( 1520 ) 3 / 2 - , $$\varDelta (1620)1/2^-$$ Δ ( 1620 ) 1 / 2 - and $$N(1650)1/2^-$$ N ( 1650 ) 1 / 2 - . The estimates based on valence quark degrees of freedom are compared with the available data, particularly with the recent Jefferson Lab data at low and large momentum transfer ( $$Q^2$$ Q 2 ). In general the estimates are in good agreement with the empirical data for $$Q^2 >2$$ Q 2 > 2 GeV $$^2$$ 2 , with a few exceptions. The results are discussed in terms of the role of the valence quarks and the meson cloud excitations for the different resonances $$N^*$$ N ∗ . We also review our results for the resonance $$\varDelta (1232)3/2^+$$ Δ ( 1232 ) 3 / 2 + and discuss the relevance of the pion cloud component for the magnetic dipole form factor and the electric and Coulomb quadrupole form factors.

### Journal

Few-Body SystemsSpringer Journals

Published: Jun 4, 2018

## You’re reading a free preview. Subscribe to read the entire article.

### DeepDyve is your personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month ### Explore the DeepDyve Library ### Search Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly ### Organize Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place. ### Access Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals. ### Your journals are on DeepDyve Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more. All the latest content is available, no embargo periods. DeepDyve ### Freelancer DeepDyve ### Pro Price FREE$49/month
\$360/year

Save searches from
PubMed

Create lists to

Export lists, citations