On strangeness production in the reactions pp -> p Lambda^0 K^+ and pn   -> n Lambda^0 K^+ near threshold
  The cross sections for the reactions pp -> p Lambda^0K^+ and pn   -> n Lambda^0K^+ are calculated near threshold of the final states. The theoretical ratio of the cross sections R = sigma(pn -> n Lambda^0K^+)/ sigma(pp ->p\Lambda^0K^+) = 3 shows the enhancement of the pn interaction with respect to the pp interaction near threshold of the strangeness production N Lambda^0K^+. Such an enhancement is caused by the contribution of the np interaction in the isospin-singlet state, which is stronger than the $pn$ interaction in the isospin-triplet state. For the confirmation of this result we calculate the cross sections for the reactions pp -> pp pi^0, pi^0 p -> Lambda^0 K^+ and pi^-p -> Lambda^0 K^0 near threshold of the final states. The theoretical cross sections agree well with the experimental data. 
A. N. Ivanov, Ya. A. Berdnikov, M. Faber, V. A. Ivanova, J. Marton, N.   I. Troitskaya