Nucleon resonances in Compton scattering

Abstract

We calculate the nucleon resonance contributions to nucleon Compton scattering, including all states with J^P = 1/2^{+-} and J^P = 3/2^{+-} where experimental data for their electromagnetic transition form factors exist. To this end, we construct a tensor basis for the Compton scattering amplitude based on electromagnetic gauge invariance, crossing symmetry and analyticity. The corresponding Compton form factors provide a Lorentz-invariant description of the process in general kinematics, which reduces to the static and generalized polarizabilities in the appropriate kinematic limits. We derive the general forms of the offshell nucleon-to-resonance transition vertices that implement electromagnetic and spin-3/2 gauge invariance, which automatically also defines onshell transition form factors that are free of kinematic constraints. We provide simple fits for those form factors, which we use to analyze the resulting Compton form factors and extract their contributions to the nucleon's polarizabilities. Apart from the Delta(1232), the resonance contributions to the scalar and spin polarizabilites are very small, although the N(1520) could play a role for the proton's magnetic polarizability.

43 pages, 20 figures, 21 tables

References in corpus (34)

• Unitary Isobar Model - MAID2007
• Baryons as relativistic three-quark bound states
• Electromagnetic excitation of the Delta(1232)-resonance
• The Proton Radius Puzzle
• Two-Photon Physics in Hadronic Processes
• Using effective field theory to analyse low-energy Compton scattering data from protons and light nuclei
• A study of the $P_{11}(1440)$ and $D_{13}(1520)$ resonances from CLAS data on $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$
• Proton polarisability contribution to the Lamb shift in muonic hydrogen at fourth order in chiral perturbation theory
• Compton scattering from the proton in an effective field theory with explicit Delta degrees of freedom
• Dynamical Coupled-Channels Effects on Pion Photoproduction
• A systematic study of longitudinal and transverse helicity amplidutes in the hypercentral Constituent Quark Model
• Contribution of spin 1/2 and 3/2 resonances to two-photon exchange effects in elastic electron-proton scattering
• D-state effects in the electromagnetic N-Delta transition
• A Covariant model for the nucleon and the $\Delta$
• Electroexcitation of the Roper resonance in the relativistic quark models
• Nucleon resonances in AdS/QCD
• Dynamical coupled-channels analysis of 1H(e,e'pi)N reactions
• Measurements of $ep\to e^{\prime }{\pi }^{+}n$ at W = 1.6 - 2.0 GeV and extraction of nucleon resonance electrocouplings at CLAS
• Measurements of Double-Polarized Compton Scattering Asymmetries and Extraction of the Proton Spin Polarizabilities
• Nucleon Compton scattering in the Dyson-Schwinger approach
• Electroproduction of the Roper resonance on the proton: the role of the three-quark core and the molecular N-sigma component
• First Lattice Study of the $N$-$P_{11}(1440)$ Transition Form Factors
• Large-$N_c$ relations for the electromagnetic N to Delta(1232) transition
• Valence quark and meson cloud contributions for the gamma* Lambda -> Lambda* and gamma* Sigma0 -> Lambda* reactions
• Neutral Pion Electroproduction in the Resonance Region at High $Q^2$
• Higher order forward spin polarizability
• ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors in the timelike regime
• Using the Single Quark Transition Model to predict nucleon resonance amplitudes
• Nucleon Resonance Structure from Exclusive Meson Electroproduction with CLAS
• Generalized polarizabilities of the nucleon in baryon chiral perturbation theory
• Semirelativistic approximation to the ${\gamma }^{\ast }N\to N(1520)$ and ${\gamma }^{\ast }N\to N(1535)$ transition form factors
• New low-$Q^2$ measurements of the ${\gamma }^{\ast }N\to \Delta (1232)$ Coulomb quadrupole form factor, pion cloud parametrizations and Siegert's theorem
• Partial-wave analysis of proton Compton scattering data below the pion-production threshold
• $\Delta (1232)$-Resonance in the Hydrogen Spectrum

Cited by in corpus (19)

• On the Equivalence of Three-Particle Scattering Formalisms
• Single pseudoscalar meson pole and pion box contributions to the anomalous magnetic moment of the muon
• Nonperturbative Ball-Chiu construction of the three-gluon vertex
• Scattering amplitudes and contour deformations
• Dynamical diquarks in the ${\mathbf{\gamma }}^{(\ast )}\mathbf{p}\to \mathbf{N}(1535){\frac{1}{2}}^{-}$ transition
• Practical scheme from QCD to phenomena via Dyson-Schwinger equations
• Electromagnetic form factors of the ${\Omega }^{-}$ baryon in the spacelike and timelike regions
• Covariant model for the Dalitz decay of the $N(1535)$ resonance
• Photo- and electro-production of narrow exotic states: from light quarks to charm and up to bottom
• Low-$Q^2$ empirical parametrizations of the $N^{\ast }$ helicity amplitudes
• Pion Photoproduction off Nucleon with Hamiltonian Effective Field Theory
• Combined parametrization of the neutron electric form factor and the ${\gamma }^{\ast }N\to \Delta (1232)$ quadrupole form factors
• Beam Spin Asymmetry in Electroproduction of Pseudoscalar or Scalar Meson Production off the Scalar Target
• Disperon QED
• Electroweak form factors of baryons in dense nuclear matter
• Quark model calculations of transition form factors at high photon virtualities
• Electromagnetic transition form factors and Dalitz decays of hyperons
• About the magnitude of the ${\gamma }^{\ast }N\to N(1520)$ transverse amplitudes near $Q^2=0$
• Getting a handle on correlation functions