4π-decays of scalar and vector mesons

Two different anti pn annihilation modes, anti pn→π-4π0 and anti pn→2π-2π0π+, are used to study the 4π-decays of scalar and vector mesons. The data are dominated by 4π scalar isoscalar interactions. At least two states are needed, the f0(1370) and the f0(1500). The 4π-decay width of the f0(1370) is more than 6 times larger than the sum of all observed partial decay widths to two pseudoscalar mesons. The state has important couplings to (ππ)S(ππ)S and to ρρ. The 4π-decays of the f0(1500) represent about half of its total width. The ρ(1450) and the ρ(1700) are observed in several 4π decay modes. The ratio of the 4π relative to the 2π decay of the ρ(1450) is in contradiction to its proposed interpretation as a pure hybrid state but it suggests that it is not a pure 23S1-state either. Our results favour the assignment of the ρ(1700) as 3D1 state, its interpretation as 33S1-state is less plausible. (orig.)