Partial wave analyses of J/ψ→γπ+π− and γπ0π0

Results are presented on J/ψ radiative decays to π+π− and π0π0 based on a sample of 58M J/ψ events taken with the BES II detector. Partial wave analyses are carried out using the relativistic covariant tensor amplitude method in the 1.0 to 2.3GeV/c2ππ mass range. There are conspicuous peaks due to the f2(1270) and two 0++ states in the 1.45 and 1.75 GeV/c2 mass regions. The first 0++ state has a mass of 1466±6±20MeV/c2, a width of 108−11+14±25MeV/c2, and a branching fraction B(J/ψ→γf0(1500)→γπ+π−)=(0.67±0.02±0.30)×10−4. Spin 0 is strongly preferred over spin 2. The second 0++ state peaks at 1765−3+4±13MeV/c2 with a width of 145±8±69MeV/c2. If this 0++ is interpreted as coming from f0(1710), the ratio of its branching fractions to ππ and KK¯ is 0.41−0.17+0.11.