e-Article
First Measurement of the $\Sigma$ Beam Asymmetry in $\eta^{\prime}$ Photoproduction off the Proton near Threshold
Document Type
Working Paper
Author
Sandri, P. Levi; Mandaglio, G.; De Leo, V.; Bartalini, O.; Bellini, V.; Bocquet, J. P.; Capogni, M.; Curciarello, F.; D'Angelo, A.; Didelez, J. P.; Di Salvo, R.; Fantini, A.; Franco, D.; Gaulard, C.; Gervino, G.; Ghio, F.; Giardina, G.; Girolami, B.; Giusa, A.; Lapik, A.; Lleres, A.; Mammoliti, F.; Manganaro, M.; Moricciani, D.; Mushkarenkov, A.; Nedorezov, V.; Randieri, C.; Rebreyend, D.; Rudnev, N.; Russo, G.; Schaerf, C.; Sperduto, M. L.; Sutera, M. C.; Turinge, A.; Vegna, V.; Zonta, I.
Source
Eur. Phys. J. A (2015) 51: 77
Subject
Language
Abstract
The $\Sigma$ beam asymmetry in $\eta^{\prime}$ photoproduction off the proton was measured at the GrAAL polarised photon beam with incoming photon energies of 1.461 and 1.480 GeV. For both energies the asymmetry as a function of the meson production angle shows a clear structure, more pronounced at the lowest one, with a change of sign around 90$^o$. The observed behaviour is compatible with P-wave D-wave (or S-wave F-wave) interference, the closer to threshold the stronger. The results are compared to the existing state-of-the-art calculations that fail to account for the data.
Comment: 6 pages, 4 figures, accepted for publication on Eur. Phys. J A
Comment: 6 pages, 4 figures, accepted for publication on Eur. Phys. J A