Isospin analysis of NN → (ΛK)N and comparison of isoscalar and isovector exchange in NN → (YK)N at 6 GeV/c

Abstract Using new data on the reaction np → Λ K 0 p the three independent charge channels for the basic reaction NN → ( Λ K)N have been investigated to obtain the two isospin amplitudes and their relative phase at 6 GeV/ c . Isospin zero exchange accounts for about 40% of the total reaction amplitude. These amplitudes are compared with those found for NN → (Σ K ) 1 2 N at 6 GeV/ c . A Deck model is shown to explain the shape of the I = 0 exchange part of the combined ΛK and (Σ K ) 1 2 mass spectrum. Isoscalar and isovector exchanges in NN → (YK)N are compared in terms of experimental distributions in t ′ = | t − t min | and the decay angles in the YK rest frame; in particular the Treiman-Yang angle distribution is flat for both exchanges for t ′ 2 or m (YK)