Partial Wave Analysis of $J/\psi\to\gamma(\pi^+\pi^-\pi^+\pi^-)$

Abstract

BES data on $J/\psi \to \gamma (\pi^{+} \pi^{-} \pi^{+} \pi^{-})$ have been analyzed into partial waves. We fit with resonances having $J^{PC}=2^{++}$ at 1275 MeV, $0^{++}$ at 1500 MeV, $2^{++}$ at 1565 MeV, $0^{++}$ at 1740 MeV, $2^{++}$ at 1940 MeV and $0^{++}$ at 2104 MeV, plus a broad $0^-$ component. The $0^{++}$ resonances decay dominantly to $\sigma\sigma$, while $2^{++}$ resonances in the high mass region decay mainly to $f_2(1270)\sigma$ and $\sigma\sigma$; $2^{++}$ resonances from the low mass region decay dominantly to $\rho\rho$.