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Related papers: $\eta$ MAID-2015: update with new data and new res…

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A combined analysis of new eta photoproduction data for total and differential cross sections, target asymmetry and photon asymmetry is presented. Using a few reasonable assumptions we perform the first model-independent analysis of the…

Nuclear Theory · Physics 2008-11-26 L. Tiator , D. Drechsel , G. Knoechlein , C. Bennhold

The photoproduction of \eta'-mesons off different nuclei has been measured with the CBELSA/TAPS detector system for incident photon energies between 1500 - 2200 MeV. The transparency ratio has been deduced and compared to theoretical…

We study the $\eta$-photoproduction focusing on the new nucleon resonance which was observed at $\sqrt{s}=1675$ MeV with a narrow decay width ($\sim 10$ MeV) in the recent GRAAL experiment. Using an effective Lagrangian approach, we compute…

High Energy Physics - Phenomenology · Physics 2009-11-11 Ki-Seok Choi , Seung-il Nam , Atsushi Hosaka , Hyun-Chul Kim

A reggeized model for \eta and \eta' photoproduction on the nucleon is presented. In this model, t-channel vector meson exchanges are described in terms of Regge trajectories to comply with the correct high energy behavior. We compare this…

Nuclear Theory · Physics 2016-09-08 Wen-Tai Chiang , Shin Nan Yang , L. Tiator , M. Vanderhaeghen , D. Drechsel

The beam asymmetry, $\Sigma$, was measured at ELSA in the reaction $\vec \gamma p \to \eta p$ using linearly polarised tagged photon beams, produced by coherent bremsstrahlung off a diamond. The crystal was oriented to provide polarised…

Nuclear Experiment · Physics 2008-11-26 D. Elsner et al.

The photo- and electroproduction of eta, eta-prime mesons on nucleons are investigated within a relativistic chiral unitary approach based on coupled channels. The s-wave potentials for electroproduction and meson-baryon scattering are…

High Energy Physics - Phenomenology · Physics 2009-11-07 B. Borasoy , E. Marco , S. Wetzel

A combined analysis of the existing data on the reactions $\gamma p \to p \eta^\prime $ and $pp \to pp\eta^\prime $, based on a relativistic meson exchange model of hadronic interactions, is presented.

Nuclear Theory · Physics 2007-05-23 K. Nakayama , H. Haberzettl

This paper presents results from partial-wave analyses of the photoproduction reactions $\gamma p \rightarrow \eta p$ and $\gamma n \rightarrow \eta n$. World data for the observables \DSG, $\Sigma$, $T$, $P$, $F$, and $E$ were analyzed as…

Nuclear Experiment · Physics 2019-05-29 B. C. Hunt , D. M. Manley

We extract a parameter $\xi$, a characteristic product of the strong and electromagnetic amplitudes for the N^*(1535), to be (2.20+-0.15) in unit of 10^(-4)MeV^(-1) from the new data on photoproduction of etas off proton.

High Energy Physics - Phenomenology · Physics 2009-10-28 Nimai C. Mukhopadhyay , J. -F. Zhang , M. Benmerrouche

A recently developed quark model approach to pseudoscalar meson photoproduction is extended to electroproduction process for the $\eta$ meson in the kinematics of momentum transfer $Q^2 \leq$ 4 (GeV/c)$^2$ and total center of mass energy $W…

Nuclear Theory · Physics 2008-11-26 Q. Zhao , B. Saghai , Z. -P. Li

Differential cross sections for eta photoproduction off protons have been measured at E_gamma = 1.6 - 2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in cross…

The unitary isobar model MAID has been extended and used for a partial wave analysis of pion photo- and electroproduction in the resonance region W < 2 GeV. Older data from the world data base and more recent experimental results from…

Nuclear Theory · Physics 2015-06-26 L. Tiator , D. Drechsel , S. Kamalov , M. M. Giannini , E. Santopinto , A. Vassallo

Coherent photoproduction of eta mesons from the deuteron has been measured from threshold up to incident photon energies of 750 MeV using the photon spectrometer TAPS at the tagged photon facility at the Mainz microtron MAMI. For the first…

We investigate photoproduction of eta mesons off protons and neutrons within a coupled-channels effective-Lagrangian method which is based on the K-matrix approach. The two-body final channels included are pi-N, eta-N, phi-N, rho-N,…

Nuclear Theory · Physics 2009-09-09 R. Shyam , O. Scholten

Incoherent photoproduction of the $\eta$-meson on the deuteron is studied for photon energies from threshold to 800 MeV. The dominant contribution, the $\gamma$N-$\eta$N amplitude, is described within an isobar model. The final state…

Nuclear Theory · Physics 2009-11-07 A. Sibirtsev , Ch. Elster , J. Haidenbauer , J. Speth

The $\gamma n \to \pi^0 n$ differential cross section evaluated for 27 energy bins span the photon-energy range 290-813 MeV (W = 1.195-1.553 GeV) and the pion c.m. polar production angles, ranging from 18 deg to 162 deg, making use of…

The data available from the A2 Collaboration at MAMI were analyzed to select the $\gamma p\to \pi^0\eta p$ reaction on an event-by-event basis, which allows for partial-wave analyses of three-body final states to obtain more reliable…