The production of K+K- pairs in proton-proton collisions at 2.83 GeV
  Differential and total cross sections for the pp -> ppK+K- reaction have been measured at a proton beam energy of 2.83 GeV using the COSY-ANKE magnetic spectrometer. Detailed model descriptions fitted to a variety of one-dimensional distributions permit the separation of the pp -> pp phi cross section from that of non-phi production. The differential spectra show that higher partial waves represent the majority of the pp -> pp phi total cross section at an excess energy of 76 MeV, whose energy dependence would then seem to require some s-wave phi-p enhancement near threshold. The non-phi data can be described in terms of the combined effects of two-body final state interactions using the same effective scattering parameters determined from lower energy data. 
Q.J. Ye, M. Hartmann, Y. Maeda, S. Barsov, M. Buescher, D. Chiladze,   S. Dymov, A. Dzyuba, H. Gao, R. Gebel, V. Hejny, A. K...
nucl-ex nucl-th