$2\pi$ production in the Giessen coupled-channel model

Abstract

We present a coupled-channel Lagrangian approach (GiM) to describe the $\pi N\to \pi N$, $2\pi N$ scattering in the resonance energy region. The $2\pi N$ production has been significantly improved by using the isobar approximation with $\sigma N$ and $\pi \Delta (1232)$ in the intermediate state. The three-body unitarity is maintained up to interference pattern between the isobar subchannels. The scattering amplitudes are obtained as a solution of the Bethe-Salpeter equation in the $K$ matrix approximation. As a first application we perform a partial wave analysis of the $\pi N\to \pi N$, ${\pi }^0{\pi }^{0}N$ reactions in the Roper resonance region. We obtain $R_{\sigma N}(1440)=27_{-9}^{+4}$\,\% and $R_{\sigma N}(1440)=12_{-3}^{+5}$\,\% for the $\sigma N$ and $\pi \Delta$ decay branching ratios of $N^{\ast }(1440)$ respectively. The extracted $\pi N$ inelasticities and reaction amplitudes are consistent with the results from other groups.

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References in corpus (13)

• Ab-initio Determination of Light Hadron Masses
• Extended Partial-Wave Analysis of piN Scattering Data
• Dynamical coupled-channel model of meson production reactions in the nucleon resonance region
• Nucleon resonances within a dynamical coupled-channels model of pi N and gamma N reactions
• Analytic properties of the scattering amplitude and resonances parameters in a meson exchange model
• A study of the $P_{11}(1440)$ and $D_{13}(1520)$ resonances from CLAS data on $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$
• New results on the Roper resonance and the P_{11} partial wave
• eta-photoproduction in the resonance energy region
• Dynamical coupled-channels study of pi N --> pi pi N reactions
• Coupled-channel analysis of $K\Sigma$ production on the nucleon up to 2.0 GeV
• The reaction pi N to pi pi N in a meson-exchange approach
• Impact of pi N --> pi pi N data on determining high-mass nucleon resonances
• The reaction pi N -> pi pi N in chiral effective field theory with explicit Delta(1232) degrees of freedom

Cited by in corpus (8)

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• Dalitz plots and lineshape of $a_1(1260)$ from a relativistic three-body unitary approach
• Towards the Minimal Spectrum of Excited Baryons
• Coupled $K^{+}\Lambda$ and $K^0\Lambda$ photoproduction off the nucleon: Consequences from the recent CLAS and MAMI data and the $N(1680)P_{11}$ narrow state
• Two-Pion production in the second resonance region in ${\pi }^{-}p$ collisions with HADES
• Photo- and electro-production of narrow exotic states: from light quarks to charm and up to bottom
• Compton scattering off proton in the third resonance region
• Complex phase structure of the meson-baryon $T$-matrix