Proton-η′ interactions at threshold

• Published in: Physics letters. B Vol. 785; no. C; pp. 626 - 630
• Main Authors: Anisovich, A.V., Burkert, V., Dugger, M., Klempt, E., Nikonov, V.A., Ritchie, B.G., Sarantsev, A.V., Thoma, U.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.10.2018; Elsevier
• Subjects: Baryon spectroscopy; Meson photoproduction; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Polarization observables; Meson photoproduction; Baryon spectroscopy; Polarization observables
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2018.06.034

Recent data on photoproduction of η′ mesons off protons have been included in the data base for the Bonn–Gatchina partial wave analysis. The real and imaginary parts of the S-wave η′p→η′p scattering amplitude in the threshold region were fit to yield the η′p scattering length and the interaction range. This new analysis found |aη′p|=(0.403±0.015±0.060) fm and a phase ϕ=(87±2)∘, while the range parameter is not well-constrained. The striking behavior of the GRAAL data on the beam asymmetry in the threshold region suggests that a narrow proton-η′ resonance might exist. However, the scattering length was found to be relatively insensitive to the possible existence of this narrow resonance.