A study of the ηηπ− and ωηπ− systems produced in the reaction π−p → pπ+π−π−4γ at 18 GeV/c Original Research Article

Preliminary results are reported on the production of ηηπ− and ωηπ− in the reaction π−p → pπ+π−π−π0η at 18 GeV/c where both π0 and η decay to 2γ. The data were obtained using the MultiParticle Spectrometer at Brookhaven National Laboratory. In the ηηπ− channel, a strong a0(980) signal decaying to ηπ− is present. The accepted ηηπ− mass spectrum exhibits a structure consistent with the mass and width to the π(1800). In the ωηπ− channel, the ωπ− mass spectrum peaks at the mass of the b1(1235).