The shape of the $\Delta$ baryon in a covariant spectator quark model

Abstract

Using a covariant spectator quark model that describes the recent lattice QCD data for the $\Delta$ electromagnetic form factors and all available experimental data on $\gamma N\to \Delta$ transitions, we analyze the charge and magnetic dipole distributions of the $\Delta$ baryon and discuss its shape. We conclude that the quadrupole moment of the $\Delta$ is a good indicator of the deformation and that the ${\Delta }^{+}$ charge distribution has an oblate shape. We also calculate transverse moments and find that they do not lead to unambiguous conclusions about the underlying shape.

Extended introduction, references added, other small modifications. To appear in Phys. Rev. D. 14 pages, 8 figures

References in corpus (15)

• Electromagnetic excitation of the Delta(1232)-resonance
• Empirical transverse charge densities in the nucleon and the nucleon-to-$\Delta$ transition
• A pure S-wave covariant model for the nucleon
• The nucleon to Delta electromagnetic transition form factors in lattice QCD
• 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 $\Delta$
• Delta and Omega electromagnetic form factors in a Dyson-Schwinger/Bethe-Salpeter approach
• Timelike gamma* N -> Delta form factors and Delta Dalitz decay
• 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
• Electromagnetic form factors of the Delta in a S-wave approach
• The neutron negative central charge density: an inclusive-exclusive connection
• A Study of Hadron Deformation in Lattice QCD

Cited by in corpus (9)

• Spectroscopy of Light Baryons: $\Delta$ Resonances
• ${\gamma }^{\ast }N\to N^{\ast }(1520)$ 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
• ${\gamma }^{\ast }N\to N(1710)$ transition at high momentum transfer
• Electromagnetic form factors of the ${\Omega }^{-}$ baryon in the spacelike and timelike regions
• Meson cloud contributions to the Dalitz decays of decuplet to octet baryons
• Electroweak form factors of baryons in dense nuclear matter
• Spectroscopy and Radiative Decays of ${\Omega }_{ccc}$ and ${\Omega }_{bbb}$ Baryons in a Quark-Diquark Model