Transition form factors: ${\gamma }^{\ast }+p\to \Delta (1232)$, $\Delta (1600)$

Abstract

Electroproduction form factors describing the ${\gamma }^{\ast }p\to {\Delta }^{+}(1232),{\Delta }^{+}(1600)$ transitions are computed using a fully-dynamical diquark-quark approximation to the Poincaré-covariant three-body bound-state problem in relativistic quantum field theory. In this approach, the $\Delta (1600)$ is an analogue of the Roper resonance in the nucleon sector, appearing as the simplest radial excitation of the $\Delta (1232)$. Precise measurements of the ${\gamma }^{\ast }p\to {\Delta }^{+}(1232)$ transition already exist on $0\le Q^2\lesssim 8$GeV${}^2$ and the calculated results compare favourably with the data outside the meson-cloud domain. The predictions for the ${\gamma }^{\ast }p\to {\Delta }^{+}(1600)$ magnetic dipole and electric quadrupole transition form factors are consistent with the empirical values at the real photon point, and extend to $Q^2\approx 6m_p^2$, enabling a meaningful direct comparison with experiment once analysis of existing data is completed. In both cases, the electric quadrupole form factor is particularly sensitive to deformation of the $\Delta$-baryons. Interestingly, whilst the ${\gamma }^{\ast }p\to {\Delta }^{+}(1232)$ transition form factors are larger in magnitude than those for ${\gamma }^{\ast }p\to {\Delta }^{+}(1600)$ in some neighbourhood of the real photon point, this ordering is reversed on $Q^2\gtrsim 2m_p^2$, suggesting that the ${\gamma }^{\ast }p\to {\Delta }^{+}(1600)$ transition is more localised in configuration space.

arXiv comment13 pages, 8 figures, 2 tables

References in corpus (67)

• pi- and K-meson Bethe-Salpeter Amplitudes
• Bethe-Salpeter Study of Vector Meson Masses and Decay Constants
• Baryons as relativistic three-quark bound states
• Excited state baryon spectroscopy from lattice QCD
• Electromagnetic excitation of the Delta(1232)-resonance
• Progress Toward Understanding Baryon Resonances
• Electroexcitation of nucleon resonances from CLAS data on single pion electroproduction
• Bridging a gap between continuum-QCD and ab initio predictions of hadron observables
• Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction
• Electroexcitation of nucleon resonances
• Baryon Current Matrix Elements in a Light-Front Framework
• Dynamical Study of the Delta Excitation in N(e,e' pi) Reactions
• Nucleon mass from a covariant three-quark Faddeev equation
• The pion: an enigma within the Standard Model
• Process-independent strong running coupling
• Flavor decomposition of the elastic nucleon electromagnetic form factors
• On unifying the description of meson and baryon properties
• Disentangling the dynamical origin of P11 Nucleon Resonances
• Nucleon electromagnetic form factors from the covariant Faddeev equation
• A study of the $P_{11}(1440)$ and $D_{13}(1520)$ resonances from CLAS data on $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$
• Determination of the E2/M1 Ratio in the γN \to Δ(1232) Transition from a Simultaneous Measurement of p(\vecγ,p)π^0 and p(\vecγ,π^+)n
• Nucleon and $\Delta$ elastic and transition form factors
• Completing the picture of the Roper resonance
• Dynamical Coupled-Channel Model of $\pi N$ Scattering in the W $\le$ 2 GeV Nucleon Resonance Region
• Effective masses of diquarks
• ${\pi }^{+}$ photoproduction on the proton for photon energies from 0.725 to 2.875 GeV
• Spectrum of light- and heavy-baryons
• Pseudovector components of the pion, pi^0 -> gamma gamma, and F_pi(q^2)
• Investigation of the conjectured nucleon deformation at low momentum transfer
• Perspective on rainbow-ladder truncation
• Baryon Spectrum from Superconformal Quantum Mechanics and its Light-Front Holographic Embedding
• Natural constraints on the gluon-quark vertex
• 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
• Measurement of the recoil polarization in the p (\vec e, e' \vec p) pi^0 reaction at the Δ(1232) resonance
• Nucleon mass and pion loops
• Dynamical Coupled-Channels Effects on Pion Photoproduction
• On light baryons and their excitations
• Quark-Model Identification of Baryon Ground and Resonant States
• A systematic study of longitudinal and transverse helicity amplidutes in the hypercentral Constituent Quark Model
• Nucleon spin structure at very high-x
• Three Lectures on Hadron Physics
• Elastic and transition form factors of the Δ(1232)
• Poincaré-covariant analysis of heavy-quark baryons
• Understanding the nucleon as a Borromean bound-state
• Nucleon-to-Roper electromagnetic transition form factors at large-$Q^2$
• Process-independent effective coupling. From QCD Green's functions to phenomenology
• Measurements of $ep\to e^{\prime }{\pi }^{+}n$ at W = 1.6 - 2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS
• Structure of the nucleon's low-lying excitations
• Nucleon to Delta electromagnetic transition in the Dyson-Schwinger approach
• Insights into the gamma* N -> Delta transition
• Electromagnetic properties of diquarks
• Electromagnetic Properties for Arbitrary Spin Particles: Part 2 $-$ Natural Moments and Transverse Charge Densities
• Parity partners in the baryon resonance spectrum
• Electroproduction of the N*(1535) resonance at large momentum transfer
• Parton distribution amplitudes: revealing diquarks in the proton and Roper resonance
• Dissecting nucleon transition electromagnetic form factors
• Measurements of the gamma*p->Delta Reaction At Low Q^2: Probing the Mesonic Contribution
• Results from the N* program at JLab
• Electromagnetic transition form factors of baryons in the space-like momentum region
• More about the light baryon spectrum
• N* Structure and Strong QCD
• Delta-to-N-gamma Coulomb Quadrupole Amplitude in PQCD
• Electroexcitation of the Delta(1232)3/2+ and Delta(1600)3/2+ in a light-front relativistic quark model
• N* Experiments and their Impact on Strong QCD Physics
• Progress in the calculation of nucleon transition form factors
• The Roper resonance: a genuine quark state or a dynamically generated structure?
• Electromagnetic multipole moments of baryons

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• Empirical Consequences of Emergent Mass
• Impressions of the Continuum Bound State Problem in QCD
• Strong QCD Insights from Excited Nucleon Structure Studies with CLAS and CLAS12
• Nucleon elastic form factors at accessible large spacelike momenta
• Jülich-Bonn-Washington Model for Pion Electroproduction Multipoles
• Electromagnetic Transition Form Factors of Baryon Resonances
• Nucleon axial-vector and pseudoscalar form factors, and PCAC relations
• Photo- and Electrocouplings of Nucleon Resonances
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• Nucleon resonances with higher spins in soft-wall AdS/QCD
• Coupled-channel analysis of pion- and eta-electroproduction with the Jülich-Bonn-Washington model
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• Contact interaction analysis of octet baryon axialvector and pseudoscalar form factors
• Composition of low-lying $\mathbf{J}={\frac{3}{2}}^{\pm }\mathbf{\Delta }$-baryons
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• Space-like Electromagnetic Form Factors of Lambda- and Sigma-Baryons from Quark-Diquark Faddeev Equations
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• ${\gamma }^{\ast }N\to {\Delta }^{+}(1600)$ transition form factors in light-cone sum rules
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