Author/Authors :
A.V. Anisovich، نويسنده , , C.A. Baker، نويسنده , , C.J. Batty، نويسنده , , D.V. Bugg، نويسنده , , A.R. Cooper، نويسنده , , C. Hodd، نويسنده , , V.A. Nikonov، نويسنده , , A.V. Sarantsev، نويسنده , , V.V. Sarantsev، نويسنده , , B.S. Zou، نويسنده ,
Abstract :
High statistics data on p̄p→ηπ0π0π0 at nine beam momenta from 900 to 1940 MeV/c require the presence of three I=0, JPC=2−+ mesons with masses and widths (i) M=1645±6(stat)±20(syst) MeV, Γ=200±7±20 MeV, (ii) M=1860±5±15 MeV, Γ=250±25±25 MeV, (iii) M=2030±5±15 MeV, Γ=205±10±15 MeV. The η2(1645) and η2(2030), together with η2(2300) observed earlier, may be interpreted as a sequence of expected q̄q states. The η2 at 1860 MeV appears to be an extra state, hence a candidate for a hybrid. Decay branching ratios of all three states to a2(1320)π, f2(1270)η and a0(980)π are established. The η2 at 1860 MeV decays dominantly to f2η and a2π, as predicted for a hybrid. The η2(2030) decays dominantly to a2π with orbital angular momentum L=2 and slightly less strongly to a2π with L=0.
