The Jülich-Bonn dynamical coupled-channel analysis of pion- and photon-induced hadronic reactions
Solution JüBo2022:
Light baryon resonances from a coupled-channel study including KΣ photoproduction
The Jülich-Bonn dynamical coupled-channel approach is extended to include KΣ photoproduction off the proton. Differential cross section and (double) polarization data for K+Σ0 and K0Σ+ are analysed simultaneously with the pion- and photon-induced production of πN, ηN, KΛ, and KΣ final states, totaling almost 72,000 data points for center-of-mass energies W<2.4 GeV. Based on the fit results the spectrum of N* and Δ resonances is extracted in terms of pole positions and residues.
The reaction π N --> ω N in a dynamical coupled-channel approach
A refined investigation on light flavour meson-baryon scattering is performed using a dynamical
coupled-channel approach, the Jülich-Bonn model, that respects unitartiy and analyticity constraints. The channel space of πN, πΔ, σN, ρN, ηN, KΛ and KΣ is extended by adding the ωN. The spectra of N* and Δ resonances are extracted in terms of complex poles of the scattering amplitudes, based on the result of a global fit to a worldwide collection of data, in the energy region from the
πN threshold to z=2.3 GeV. A negative value of the ωN elastic scattering length is extracted. This does
not support the existence of bound states of the ω meson in nuclear matter.
The impact of K+Λ photoproduction on the resonance spectrum
The Jülich-Bonn coupled-channel framework is extended to K+Λ photoproduction. The spectrum of nucleon and Δ resonances is extracted from simultaneous fits to several
pion-induced reactions in addition to pion, eta and K+Λ photoproduction off the proton.
More than 40,000 data points up to a center-of-mass energy of E~2.3 GeV including recently measured double-polarization observables are analyzed.
[please refer to Eur. Phys. J. A 54, 110 (2018) or arXiv:1801.10458]
Analysis of new polarization data in pion photoproduction
New measurements by the CBELSA/TAPS collaboration of the polarization observables T, E, P, G, and H in γp → π0p were included in the coupled-channels JüBo fits.
[please refer to Eur.Phys.J. A52 (2016) 284]
- Comparison of the Jülich2016-1 solution with pion photoproduction data: γp → π0pγp → π+p
- Comparison of the Jülich2016-1 solution with eta photoproduction data: γp → ηp
Eta photoproduction in a combined analysis of pion- and photon-induced reactions
The
resonance spectrum and its properties are determined in a combined analysis
of eta and pion photoproduction off the proton together with the reactions πN → πN, ηN, KΛ and KΣ.
[please refer to Eur.Phys.J. A51 (2015) 70]
- Comparison of the Jülich2015 solution with eta photoproduction data: γp → ηp
- Comparison of the Jülich2015 solution with pion photoproduction data: γp → π0pγp → π+p
- Comparison of the Jülich2015 solution with inelastic piN scattering data: πN → ηN, KΛ, KΣ
Photocouplings at the pole from pion photoproduction
Photocouplings at the pole are extracted from a combined analysis of the reactions γp → π0p and γp → π+n. The Jülich2012 dynamical coupled-channel model is employed as the hadronic final-state interaction. [please refer to Eur. Phys. J. A50 (2014) 101]
Comparison of the Jülich2013 solution with pion photoproduction data:
Coupled-channel dynamics in the reactions πN → πN, ηN, KΛ, KΣ
Elastic πN scattering and the reactions π-p → ηn, K0Λ, K0Σ0, K+Σ- and π+p → K+Σ+ are analyzed simultaneously and the resonance content in terms of pole positions and residues is determined. [please refer to Eur. Phys. J.
A49 (2013) 44]
Partial wave amplitudes of the Jülich2012 solution:
For each partial wave L2I2J the partial wave amplitudes τ
for fit A and B are given in the table below, for all on-shell transitions among the channels πN, ηN, KΛ, KΣ.
The ordering of the columns of the individual tables ( L2I2J.txt
files) is defined in this comment .
Further information, such as the definition of τ
its relations to observables and the threshold energies can be foundhere.