Energy Dependence of the Near-Threshold Total Cross-Section for the pp->pp eta' Reaction


Total cross sections for the pp->pp eta' reaction have been measured in the excess energy range from Q=1.53 MeV to Q=23.64 MeV. The experiment has been performed at the internal installation COSY-11 using a stochastically cooled proton beam of the COoler SYnchrotron COSY and a hydrogen cluster target. The determined energy dependence of the total cross section weakens the hypothesis of the S-wave repulsive interaction between the eta' meson and the proton. New data agree well with predictions based on the phase-space distribution modified by the proton-proton final-state-interaction (FSI) only.

Preprint: FZJ-IKP(I)-2000-1 in PostScript format (325kB)
Publication: Phys.Lett. B 474 (2000) 416-422