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. 
P. Moskal, H.-H. Adam, J.T. Balewski, V. Baru, A. Budzanowski, D.   Grzonka, J. Haidenbauer, L. Jarczyk, A. Khoukaz, K. Kili...