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 more than 67,000 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.

[please refer to arXiv:2208.00089 [nucl-th]]




 
Solution JüBo_omegaN:

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.

[please refer to Y.-F. Wang et al., arXiv:2208.03061 [nucl-th]]




 
Solution JüBo2017:

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]




 
Solution JüBo2016-1:

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 → π0p      γp → π+p

- Comparison of the Jülich2016-1 solution with eta photoproduction data:   γp → ηp

- Download photoproduction multipoles:  γp → π0p      γp → π+p      γp → ηp


 
Solution Jülich2015:

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 → π0p      γp → π+p

- Comparison of the Jülich2015 solution with inelastic piN scattering data:   πN → ηN, KΛ, KΣ

- Photoproduction multipoles:   γp → π0p      γp → π+p      γp → ηp

                                                     γN → πN (I=1/2)     γN → πN (I=3/2)

- πN → πN partial-wave amplitudes:   πN → πN


 

Solution Jülich2013:

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:

γp → π0p                              γp → π+p


 

Solution Jülich2012:

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 found here.
 
S11   A    P11   A     B
S31   A    B
P31   A     B
P13   A    B D13   A    B P33   A    B D33   A    B
D15   A    B F15   A    B D35   A    B F35   A    B
F17   A    B G17   A    B F37   A    B G37   A    B
G19   A    B H19   A    B G39   A    B H39   A    B

  All partial waves can be downloaded at once .



Acknowledgements:

The authors gratefully acknowledge the computing time granted on the supercomputer JURECA at Jülich Supercomputing Centre (JSC).


Impressum       Deborah Rönchen, IAS-4, Forschungszentrum Jülich, 52425 Jülich, Germany
                          Michael Döring, GWU, 725 21st ST NW, Washington DC 20052, USA


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