Double Pion Photoproduction on the Nucleon: Study of the Isospin Channels

Abstract

A model for the gamma p ----> pion+ pion- p reaction developed earlier is extended to account for all isospin channels. The model includes N, Delta(1232), N^*(1440) and N^*(1520) as intermediate baryonic states and the rho-meson as an intermediate two pion resonance. Although many terms contribute to the cross section, some channels exhibit particular sensitivity to certain mechanisms of resonance excitation or decay and the reactions provide novel information on such mechanisms. In particular the gamma N ----> N^*(1520) ----> Delta(1232) pion process affects all the channels and is a key ingredient in the interpretation of the data. Comparison is made with all available data and the agreement is good in some channels. The remaining discrepancies in some other channels are discussed.

23 pages, 13 figures. TeX, Version 3.141 [PD VMS 3.4/CERN 1.0]

References in corpus (2)

• Threshold Two-Pion Photo- and Electroproduction: More neutrals than expected
• Double Pion Photoproduction in Nuclei

Cited by in corpus (73)

• Transport-theoretical Description of Nuclear Reactions
• Baryon spectroscopy
• Chiral Unitary approach to meson-meson and meson-baryon interactions and nuclear applications
• Dynamical coupled-channel model of meson production reactions in the nucleon resonance region
• Study of Non-Strange Baryon Resonances with Meson Photoproduction
• Vector meson production and nucleon resonance analysis in a coupled-channel approach for energies m_N < sqrt(s) < 2 GeV II: photon-induced results
• Many Body approach to the inclusive $(e,e^{\prime })$ reaction from the quasielastic to the $\Delta$ excitation region
• New results on the Roper resonance and the P_{11} partial wave
• Theoretical study of the N N --> N N pi pi reaction
• Double pion photoproduction on nucleon and deuteron
• Chiral dynamics in the gamma p --> pi^0 eta p and gamma p --> pi^0 K^0 Sigma^+ reactions
• Photoproduction of pi0-mesons from nuclei
• Phenomenological analysis of the double pion production in nucleon-nucleon collisions up to 2.2 GeV
• High statistics study of the reaction $\gamma p\to p2{\pi }^0$
• The role of Delta(1700) excitation and rho production in double pion photoproduction
• Beam-Helicity Asymmetries in Double-Charged-Pion Photoproduction on the Proton
• Model Analysis of the $ep\to e{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction Reaction on the Proton
• Effective Lagrangian Approach to pion photoproduction from the nucleon
• Photoproduction of mesons off nuclei
• Spin Asymmetry and Gerasimov-Drell-Hearn Sum Rule for the Deuteron
• An explanation of the ${\Delta }_{5/2^{-}}(1930)$ as a $\rho \Delta$ bound state
• Study of the gamma p --> pi0 pi0 p reaction with the Crystal Ball/TAPS at the Mainz
• Beam-Helicity Asymmetries in Double Pion Photoproduction off the Proton
• Photoproduction of pi0pi0 and pi0pi+-pairs off the proton from threshold to the second resonance region
• Double ${\pi }^0$ Photoproduction off the Proton at Threshold
• Study of polarization observables in double pion photoproduction on the proton
• Double and single pion photoproduction within a dynamical coupled-channels model
• Electroproduction of p π^{+} π^{-} off protons at 0.2<Q^{2}<0.6 GeV^{2} and 1.3<W<1.57 GeV with CLAS
• Low-energy pions in nuclear matter and 2pi photoproduction within a BUU transport model
• Measurement of the beam-helicity asymmetry $I^{\odot }$ in the photoproduction of ${\pi }^0$-pairs off the proton and off the neutron
• In-medium properties of the D13(1520) nucleon resonance
• Low-energy pi pi photoproduction off nuclei
• Evaluation of the polarization observables I^S and I^C in the reaction gamma p --> pi^0 eta p
• The two pion decay of the Roper resonance
• Surface and volume effects in the photoabsorption of nuclei
• The Generalized Gerasimov-Drell-Hearn Integral and the Spin Structure of the Nucleon
• Photoproduction of mesons from nuclei - In-medium properties of hadrons
• Double neutral pion photoproduction at threshold
• The reaction pi N to pi pi N in a meson-exchange approach
• Helicity asymmetries in double pion photoproduction on the proton
• A model for pion Delta electroproduction on the proton
• Polarization observables in ${\pi }^0\eta$-photoproduction on the proton
• Spin Information from Vector-Meson Decay in Photoproduction
• Mesonic Content of the Nucleon and the Roper Resonance
• Analysis of angular distributions in gamma N \to pi0 eta N
• Photoproduction of scalar mesons on protons and nuclei
• The width of the omega meson in the nuclear medium
• The pi N -> pi pi N reaction around the N(1440) energy
• Constraints on vector meson photoproduction spin observables
• Tensor meson photoproduction as a final state interaction effect
• First measurement of target and beam-target asymmetries in the $\gamma p\to {\pi }^0\eta p$ reaction
• Helicity-dependent cross sections for the photoproduction of ${\pi }^0$ pairs from nucleons
• On the background in the $\gamma p\to \omega ({\pi }^0\gamma )p$ reaction and mixed event simulation
• Isocalar Roper excitation in the pp --> pp pi0 reaction close to threshold
• Coherent two pion photoproduction on 12C
• Theory of two-pion photo- and electroproduction off the nucleon
• An event mixing technique for Bose-Einstein correlations of two pions in photoproduction around 1 GeV
• Partial wave expansion for photoproduction of two pseudoscalars on a nucleon
• Two Pion Production in Photon Induced Reactions
• Chiral perturbation theory calculation for pn -> dpipi at threshold
• Chiral Symmetry and N*(1440) -> N pi pi Decay
• The electro production of d* dibaryon
• Physics at ELSA, achievements and future
• Theoretical study of the $\gamma d\to {\pi }^0\eta d$ reaction
• Semihadronic and hadronic decays of ${\rho }^0$ and $\omega$ mesons coherently photoproduced in the isoscalar nuclei
• Electroproduction of the d* dibaryon
• $\omega (\to {\pi }^{+}{\pi }^{-}{\pi }^0)$ meson photoproduction on proton
• ${\pi }^0\gamma$ invariant mass distribution in the low energy $\gamma p\to \omega p$ reaction
• Helicity dependent cross sections for the photoproduction of ${\pi }^0{\pi }^{\pm }$ pairs from quasi-free nucleons
• Photoproduction of neutral pion pairs in the Coulomb field of the nucleus
• Complete experiment problem for photoproduction of two pseudoscalar mesons on a nucleon in a truncated partial-wave analysis
• Experimental Review of Baryons in the Nuclear Medium
• Double Pion Photoproduction from Nuclei