But, on inspecting S matrix for poles, we discovered (early 1980s) also: Isospin (qqbar) pole(s) (MeV) experiment   I=1 (nnbar)     968 - 28 i   a0(980)   I=1/2 (snbar)     727 - 263 i   K0*(800)   I=0 (nnbar and ssbar)     470 - 208 i   994 - 20 i   f0(600)   f0(980)                                 The low-lying scalar nonet.                                    Zeitschrift für Physik C30, 615 (1986) with parameters deduced from c-cbar, b-bbar and light vector states.