Isospin Dependence of the η′ Meson Production in Nucleon-Nucleon Collisions.

According to the quark model, the masses of η and η′ mesons should be almost equal. However, the empirical values of these masses differ by more than a factor of two. Similarly, though they have almost the same quark-antiquark content, the total cross section for the creation of these mesons close to the kinematical thresholds in the pp → ppX reaction differs significantly. Using the COSY-11 detection setup we intend to determine whether this difference will also be so significant in the case of the production of these mesons in the proton-neutron scattering. Additionally, the comparison of the pp → ppη′ and pn → pnη′ total cross sections will allow to learn about the production of the η′ meson in the channels of isospin I = 0 and I = 1 and to investigate aspects of the gluonium component of the η′ meson. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]