Observation of pseudoscalar and axial vector resonances in π−p→K+K−π0nat 18 GeV

The number of pseudoscalar mesons in the mass range from 1400 to 1500 MeV/c2has been a subject of considerable interest for many years, with several experiments having presented evidence for two closely spaced states. A new measurement of the reaction π−p→K+K−π0nhas been made at a beam energy of 18 GeV. A partial wave analysis of the K+K−π0system shows evidence for three pseudoscalar resonances, η(1295), η(1416), and η(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an IGJPC=1+1−−state previously reported in φπ0decay.