Light Baryon Spectroscopy

Abstract

This review treats the advances in Light Baryon Spectroscopy of the last two decades, which were mainly obtained by measuring meson-production reactions at photon facilities all over the world. We provide a consistent compendium of experimental results, as well as a review of the theoretical methods of amplitude analysis used to analyze the data. The most significant datasets are presented in detail and are listed in combination with a full set of the relevant references. In addition, a brief summary of spin-formalisms, which are ubiquitous in Light Baryon Spectroscopy, as well as a review on complete experiments, are provided. The synthesis of the reviewed knowledge is presented in a full interpretation of the new results on the Light Baryon Spectrum.

142 pages, 52 figures, 19 tables; Version 1 has been accepted for publication in "Progress in Particle and Nuclear Physics"; Version 2 contains further detail improvements

References in corpus (85)

• Infrared Properties of QCD from Dyson-Schwinger equations
• Unitary Isobar Model - MAID2007
• Baryons as relativistic three-quark bound states
• Extended Partial-Wave Analysis of piN Scattering Data
• Light-Front Holography: A First Approximation to QCD
• Dynamical coupled-channel model of meson production reactions in the nucleon resonance region
• Analytic properties of the scattering amplitude and resonances parameters in a meson exchange model
• Three-body Unitarity in the Finite Volume
• Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)
• Diffractive $\varphi$-meson photoproduction on proton near threshold
• Dynamical Coupled-Channel Model of $\pi N$ Scattering in the W $\le$ 2 GeV Nucleon Resonance Region
• Evidence for a narrow structure at W~1.68 GeV in eta photoproduction on the neutron
• New results on the Roper resonance and the P_{11} partial wave
• On the nature of $a_1(1420)$
• Measurement of eta photoproduction on the proton from threshold to 1500 MeV
• Eta photoproduction in a combined analysis of pion- and photon-induced reactions
• Measurement of the reaction gamma p --> K0 Sigma+ at photon energies up to 2.6 GeV
• Measurement of the beam asymmetry in eta-photoproduction off the proton
• Quasi-free photoproduction of eta-mesons of the neutron
• eta-photoproduction in the resonance energy region
• Two-pole structures in QCD: Facts, not fantasy!
• Study of psi(2S) Decays to gamma p bar{p}, pi^0 p bar{p} and eta p bar{p} and Search for p bar{p} Threshold Enhancements
• Three-body Unitarity with Isobars Revisited
• Measurement of beam-recoil observables Ox, Oz and target asymmetry for the reaction gamma p -> K Lambda
• On light baryons and their excitations
• The reaction pi+ p --> K+ Sigma+ in a unitary coupled-channels model
• Kaon photoproduction in a multipole approach
• Differential cross section and photon beam asymmetry for the gamma n -> K+ Sigma- reaction at Egamma=1.5-2.4 GeV
• Data analysis techniques, differential cross sections, and spin density matrix elements for the reaction $\gamma p\to \varphi p$
• Nucleon resonance decay by the $K^0{\Sigma }^{+}$ channel
• Quasifree photoproduction of $\eta$ mesons off protons and neutrons
• Photoproduction of the $\omega$ meson off the proton near threshold
• Linearly polarised photon beams at ELSA and measurement of the beam asymmetry in pi^0-photoproduction off the proton
• Photoproduction of eta-mesons on the deuteron above S11(1535) in the presence of a narrow P11(1670) resonance
• Evidence for a parity doublet Delta(1920)P_{33} and Delta(1940)D_{33}$ from γp\to pπ^0η
• Relevance of complex branch points for partial wave analysis
• Photoproduction of eta meson within a coupled-channels K-matrix approach
• Study of the gamma p --> pi0 pi0 p reaction with the Crystal Ball/TAPS at the Mainz
• Measurement of the transverse target and beam-target asymmetries in $\eta$ meson photoproduction at MAMI
• 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
• Radiative pi0 photoproduction on protons in the Delta+(1232) region
• Strong evidence for nucleon resonances near 1900\,MeV
• Octet and Decuplet masses: a covariant three-body Faddeev calculation
• Evidence for the $N^{\prime }(1720)3/2^{+}$ Nucleon Resonance from Combined Studies of CLAS ${\pi }^{+}{\pi }^{-}p$ Photo- and Electroproduction Data
• Pole positions and residues from pion photoproduction using the Laurent+Pietarinen expansion method
• Measurement of the Differential and Total Cross Sections of the $\gamma d\to K^0\Lambda (p)$ Reaction within the Resonance Region
• The N(1520) 3/2- helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions
• Insight into the narrow structure in {\boldmath{$\eta$}}-photoproduction on the neutron from helicity dependent cross sections
• The $\sigma$-meson: four-quark vs. two-quark components and decay width in a Bethe-Salpeter approach
• Information Content of Polarization Measurements
• Photoproduction of pi0-mesons off neutrons in the nucleon resonance region
• Differential Cross Section Measurements for $\gamma n\to {\pi }^{-}p$ Above the First Nucleon Resonance Region
• Beam asymmetry in near threshold omega photoproduction off the proton
• Evaluation of the polarization observables I^S and I^C in the reaction gamma p --> pi^0 eta p
• First measurement of the polarization observable $E$ and helicity-dependent cross sections in single ${\pi }^0$ photoproduction from quasi-free nucleons
• More about the light baryon spectrum
• Backward-angle photoproduction of ${\pi }^0$ mesons on the proton at $E_{\gamma }$ = 1.5--2.4 GeV
• Measurement of the beam-helicity asymmetry $I^{\odot }$ in the photoproduction of ${\pi }^0{\pi }^{\pm }$-pairs off protons and off neutrons
• Pion-nucleon charge-exchange amplitudes above 2 GeV
• Beam asymmetry $\Sigma$ measurements on the ${\pi }^{-}$ photoproduction off neutrons
• Regge phenomenology in ${\pi }^0$ and $\eta$ photoproduction
• $N^{\ast }\to N{\eta }^{\prime }$ decays from photoproduction of ${\eta }^{\prime }$-mesons off protons
• Two-Pion production in the second resonance region in ${\pi }^{-}p$ collisions with HADES
• Polarization observables in ${\pi }^0\eta$-photoproduction on the proton
• $\varphi$ photoproduction on the proton at $E_{\gamma }$ = 1.5 - 2.9 GeV
• Amplitude extraction in pseudoscalar-meson photoproduction: towards a situation of complete information
• Evidence for narrow resonant structures at $W\approx 1.68$ and $W\approx 1.72$ GeV in real Compton scattering off the proton
• Differential cross section and photon beam asymmetry for the gamma p -> pi+ n reaction at forward pi+ angles at Egamma=1.5-2.95 GeV
• Photon beam asymmetry $\Sigma$ in the reaction $\vec{\gamma }p\to p\omega$ for $E_{\gamma }$ = 1.152 to 1.876 GeV
• Pionic charge exchange on the proton from 40 to 250 MeV
• Photon asymmetry measurements of $\overrightarrow{\gamma }\mathrm{p}\to {\pi }^0\mathrm{p}$ for E${}_{\gamma }$=320$-$650 MeV
• Measurement of polarisation observables in $K_s^0{\Sigma }^{+}$ photoproduction off the proton
• Single-energy amplitudes for pion photoproduction in the first resonance region
• Complete set of observables for photoproduction of two pseudoscalars on a nucleon
• The complete experiment problem of pseudoscalar meson photoproduction in a truncated partial wave analysis
• Minimal complete sets for two pseudoscalar meson photoproduction
• New result on phase shift analysis
• Helicity-dependent cross sections for the photoproduction of ${\pi }^0$ pairs from nucleons
• Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies
• Transverse Polarization of ${\Sigma }^{+}(1189)$ in Photoproduction on a Hydrogen Target in CLAS
• The ANL-Osaka Partial-Wave Amplitudes of $\pi N$ and $\gamma N$ Reactions
• Separating Signals from Non-Interfering Backgrounds using Probabilistic Event Weightings
• Physics Opportunities with Meson Beams for EIC
• Strangeness Photoproduction at the BGO-OD experiment