A t-channel isospin analysis of the chew-low plot for NN → N(Nπ) interactions at 5.7 GeV/c

A new approach to the t-channel isospin analysis of ZN → Z′(Nπ) reactions is presented. This approach, useful for Z = N, N, K− when only five independent sets of data are availables, is used to analyse data of NN → N(Nπ) reactions obtained in a pp → NNπ experiment at 5.7 GeV/c and a pd → NNπps experiment at 5.5 GeV/c. the t behaviour of the different isospin exchange amplitudes, suggests their exchange mechanism production. The mass spectrum, MπN, of the contributions produced by exchanged isospin Iex = 1, shows enhancements corresponding to N(1490) N(1670) and Δ(1230) isobars, while the mass spectrum for Iex = 0 presents only a large bump at ∼1350 MeV commonly identified as N∗(1400).