Valence quark and meson cloud contributions to the ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors

Abstract

The covariant spectator quark model is applied to the ${\gamma }^{\ast }N\to N^{\ast }(1520)$ reaction. The valence quark contributions to the electromagnetic form factors and helicity transition amplitudes are estimated from the covariant structure of the $N^{\ast }(1520)$ wave function calibrated by the experimental data for large squared momentum transfer $Q^2$. The difference between the model results and the experimental data is then used to parameterize the low $Q^2$ behavior, where meson cloud effects are assumed to dominate. This parametrization can be very useful for future studies of the reaction, as well as for the extension of the transition form factors to the timelike region.

Published in PRD. 25 pages, 7 figures

References in corpus (21)

• Unitary Isobar Model - MAID2007
• Electromagnetic excitation of the Delta(1232)-resonance
• A study of the $P_{11}(1440)$ and $D_{13}(1520)$ resonances from CLAS data on $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$
• Dynamical Coupled-Channels Effects on Pion Photoproduction
• A pure S-wave covariant model for the nucleon
• Extraction and Interpretation of gamma N --> Delta Form Factors within a Dynamical Model
• A systematic study of longitudinal and transverse helicity amplidutes in the hypercentral Constituent Quark Model
• Dilepton production in proton-induced reactions at SIS energies with the GiBUU transport model
• D-state effects in the electromagnetic N-Delta transition
• A relativistic quark model for the Omega- electromagnetic form factors
• A Covariant model for the nucleon and the $\Delta$
• Octet baryon electromagnetic form factors in nuclear medium
• Timelike gamma* N -> Delta form factors and Delta Dalitz decay
• Confinement, quark mass functions, and spontaneous chiral symmetry breaking in Minkowski space
• Extracting the Omega- electric quadrupole moment from lattice QCD data
• Valence quark and meson cloud contributions for the gamma* Lambda -> Lambda* and gamma* Sigma0 -> Lambda* reactions
• Fixed-axis polarization states: covariance and comparisons
• What is the role of the meson cloud in the ${\Sigma }^{\ast 0}\to \gamma \Lambda$ and ${\Sigma }^{\ast }\to \gamma \Sigma$ decays?
• Covariant spectator quark model description of the ${\gamma }^{\ast }\Lambda \to {\Sigma }^0$ transition
• The shape of the $\Delta$ baryon in a covariant spectator quark model
• A chiral quark model for meson electro-production in the region of D-wave resonances

Cited by in corpus (23)

• New Results from the Studies of the $N(1440)1/2^{+}$, $N(1520)3/2^{-}$, and $\Delta (1620)1/2^{-}$ Resonances in Exclusive $ep\to e^{\prime }{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction with the CLAS Detector
• Measurements of $ep\to e^{\prime }{\pi }^{+}n$ at W = 1.6 - 2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS
• Strong QCD Insights from Excited Nucleon Structure Studies with CLAS and CLAS12
• Rôle of the pion electromagnetic form factor in the $\Delta (1232)\to {\gamma }^{\ast }N$ timelike transition
• Electromagnetic Transition Form Factors of Baryon Resonances
• Axial form factors of the octet baryons in a covariant quark model
• Nucleon resonances in Compton scattering
• ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors in the timelike regime
• Using the Single Quark Transition Model to predict nucleon resonance amplitudes
• Semirelativistic approximation to the ${\gamma }^{\ast }N\to N(1520)$ and ${\gamma }^{\ast }N\to N(1535)$ transition form factors
• Valence quark contributions for the ${\gamma }^{\ast }N\to N(1440)$ form factors from Light-Front holography
• Improved empirical parametrizations of the ${\gamma }^{\ast }N\to \Delta (1232)$ and ${\gamma }^{\ast }N\to N(1520)$ helicity amplitudes and the Siegert's theorem
• $N^{\ast }$ Form Factors based on a Covariant Quark Model
• Electromagnetic form factors of the ${\Omega }^{-}$ baryon in the spacelike and timelike regions
• Covariant model for the Dalitz decay of the $N(1535)$ resonance
• Low-$Q^2$ empirical parametrizations of the $N^{\ast }$ helicity amplitudes
• Weak interaction axial form factors of the octet baryons in nuclear medium
• Electroweak form factors of baryons in dense nuclear matter
• Quark model calculations of transition form factors at high photon virtualities
• A Relativistic Model for the Electromagnetic Structure of Baryons from the 3rd Resonance Region
• About the magnitude of the ${\gamma }^{\ast }N\to N(1520)$ transverse amplitudes near $Q^2=0$
• Helicity amplitudes of $N(1520)$ and $N(1535)$ including pentaquark components
• A covariant model for the negative parity resonances of the nucleon