Differential cross sections for the reactions gamma p-> p eta and gamma p -> p eta-prime

The CLAS collaboration Williams, M. ; Krahn, Z. ; Applegate, D. ; et al.
Phys.Rev.C 80 (2009) 045213, 2009.
Inspire Record 830257 DOI 10.17182/hepdata.52983

High-statistics differential cross sections for the reactions gamma p -> p eta and gamma p -> p eta-prime have been measured using the CLAS at Jefferson Lab for center-of-mass energies from near threshold up to 2.84 GeV. The eta-prime results are the most precise to date and provide the largest energy and angular coverage. The eta measurements extend the energy range of the world's large-angle results by approximately 300 MeV. These new data, in particular the eta-prime measurements, are likely to help constrain the analyses being performed to search for new baryon resonance states.

104 data tables

Differential cross section for the W range 1.68 to 1.69 GeV.

Differential cross section for the W range 1.69 to 1.70 GeV.

Differential cross section for the W range 1.70 to 1.71 GeV.

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eta photoproduction on the proton revisited: Evidence for a narrow N(1685) resonance?

Kuznetsov, V. ; Polyakov, M. ; Boiko, T. ; et al.
2007.
Inspire Record 745642 DOI 10.17182/hepdata.41745

Revised analysis of $\Sigma$ beam asymmetry for $\eta$ photoproduction on the free proton reveals a resonant structure at $W\sim 1.69$ GeV. Comparison of experimental data with multipole decomposition based on the E429 solution of the SAID partial wave analysis and including narrow states, suggests a narrow ($\Gamma \leq 15$ MeV) resonance. Possible candidates are $P_{11}$, $P_{13}$, or $D_{13}$ resonances. The result is considered in conjunction with the recent evidence for a bump-like structure at $W\sim 1.67 - 1.68$ GeV in quasi-free $\eta$ photoproduction on the neutron.

5 data tables

Measured beam asymmetry for a mean scattering angle of 43 degrees.

Measured beam asymmetry for a mean scattering angle of 65 degrees.

Measured beam asymmetry for a mean scattering angle of 85 degrees.

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Evidence for a narrow structure at W approx. 1.68-GeV in eta photoproduction on the neutron.

The GRAAL collaboration Kuznetsov, Viacheslav ; Churikova, S. ; Gervino, G. ; et al.
Phys.Lett.B 647 (2007) 23-29, 2007.
Inspire Record 720508 DOI 10.17182/hepdata.26995

New results on quasi-free $\eta$ photoproduction on the neutron and proton bound in a deuteron target are presented. The $\gamma n \to \eta n$ quasi-free cross section reveals a bump-like structure which is not seen in the cross section on the proton. This structure may signal the existence of a relatively narrow ($M\sim 1.68$ GeV, $\Gamma \leq 30$ MeV) baryon state.

6 data tables

Quasi free differential cross section for the reaction GAMMA N --> ETA N at COS(THETA(CM)) from -0.9 to -0.5.

Quasi free differential cross section for the reaction GAMMA N --> ETA N at COS(THETA(CM)) from -0.3 to 0.1.

Quasi free differential cross section for the reaction GAMMA N --> ETA N at COS(THETA(CM)) from 0.1 to 0.5.

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