The Σ beam asymmetry in η’ photoproduction off the proton was measured at the GRAAL polarized photon beam with incoming photon energies of 1.461 and 1.480 GeV. For both energies the asymmetry as a function of the meson emission angle shows a clear structure, more pronounced at the lowest one, with a change of sign around 90°. The results are compared to the existing theories that fail to account for the data.
P. Levi Sandri, G. Mandaglio, O. Bartalini, V. Bellini, J. P. Bocquet, M. Capogni, F. Curciarello, A. D’Angelo, V. De Leo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, C. Gaulard, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Lapik, A. Lleres, F. Mammoliti, M. Manganaro, D. Moricciani, A. Mushkarenkov, V. Nedorezov, C. Randieri, D. Rebreyend, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna and I. Zonta (2014).
The European Physical Journal A, Hadrons and Nuclei – July 2015, Vol. 51, Issue 77, pp. 1-5, ISSN: 1434-6001, doi: 10.1140/epja/i2015-15077-0.
The European Physical Journal (EPJ) is a series of peer-reviewed journals indexed in all major citation databases, and covering the whole spectrum of pure and applied physics, including related interdisciplinary subjects. In particular, The European Physical Journal A (EPJ A) presents new and original research results in Hadron physics and Nuclear physics, in a variety of formats, including Regular Articles, Reviews, Tools for Experiment and Theory/Scientific Notes and Letters.