Comparison of inclusive K+ production in proton-proton and   proton-neutron collisions
  The momentum spectra of K+ produced at small angles in proton-proton and proton-deuteron collisions have been measured at four beam energies, 1.826, 1.920, 2.020, and 2.650 GeV, using the ANKE spectrometer at COSY-Juelich. After making corrections for Fermi motion and shadowing, the data indicate that K+ production near threshold is stronger in pp- than in pn-induced reactions. However, most of this difference could be made up by the unobserved K0 production in the pn case. 
Yu. Valdau, V. Koptev, S. Barsov, M. Buescher, A. Dzyuba, M. Hartmann,   A. Kacharava, I. Keshelashvili, A. Khoukaz, S. Miki...
nucl-ex hep-ex nucl-th