Toward a unified description of hadro- and photoproduction: S-wave pi- and eta-photoproduction amplitudes

Abstract

The Chew-Mandelstam parameterization, which has been used extensively in the two-body hadronic sector, is generalized in this exploratory study to the electromagnetic sector by simultaneous fits to the pion- and eta-photoproduction S-wave multipole amplitudes for center-of-mass energies from the pion threshold through 1.61 GeV. We review the Chew-Mandelstam parameterization in detail to clarify the theoretical content of the SAID hadronic amplitude analysis and to place the proposed, generalized SAID electromagnetic amplitudes in the context of earlier employed parameterized forms. The parameterization is unitary at the two-body level, employing four hadronic channels and the gamma-N electromagnetic channel. We compare the resulting fit to the MAID parameterization and find qualitative agreement though, numerically, the solution is somewhat different. Applications of the extended parameterization to global fits of the photoproduction data and to global fits of the combined hadronic and photoproduction data are discussed.

9 pages, 9 figures; added figures and text

References in corpus (9)

• Unitary Isobar Model - MAID2007
• Extended Partial-Wave Analysis of piN Scattering Data
• Upgrade of the Glasgow photon tagging spectrometer for Mainz MAMI-C
• Photoproduction of $\eta$ and $\eta \prime$ Mesons off Protons
• Dynamical Coupled-Channel Model of $\pi N$ Scattering in the W $\le$ 2 GeV Nucleon Resonance Region
• Differential cross sections for the reactions gamma p-> p eta and gamma p -> p eta-prime
• Measurement of the beam asymmetry in eta-photoproduction off the proton
• Model-independent resonance parameter extraction using the trace of K and T matrices
• Resonance parameters from K-matrix and T-matrix poles

Cited by in corpus (8)

• Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)
• Unified Chew-Mandelstam SAID analysis of pion photoproduction data
• Parameterization dependence of T matrix poles and eigenphases from a fit to piN elastic scattering data
• Photocouplings at the Pole from Pion Photoproduction
• Updated SAID analysis of pion photoproduction data
• On the effect of excited states in lattice calculations of the nucleon axial charge
• Fixed-t analyticity as a constraint in single energy partial wave analyses of meson photoproduction reactions
• Opposite parity fermion mixing and baryons $1/2^{\pm }$