Search for exotic mesons in positive pion negative pions neutral pions decay

Results from a partial wave analysis on the π+π −π0 system produced in the reaction γ p → pπ+π− π0 with beam energy in the range [4.8, 5.5] GeV/c are presented. The data were collected in CLAS experiment E01–017(G6C) at the Thomas Jefferson National Accelerator Facility. The partial wave analysis showed photo-excitation of an IGJPC = 1−1−+ exotic isovector resonance. A mass dependent analysis was performed and yielded M = 1690 ± 5 ± 7 MeV/c2 and Γ = 268 ± 14 ± 42 MeV/c2 for this state. An exotic isoscaler signal with IGJ PC = 0−2+− was also seen in the partial wave analysis with M = 2021 ± 17 ± 6 MeV/c2 and Γ = 184 ± 25 ± 26 MeV/c2. A mass dependent fit was applied to other non-exotic signals as well, including I GJPC = 1−1++ and 0−1−−. Resonance parameters were extracted for those states also.