A study of J/ψ→V (ρ,φ) decays with the BESII detector

Using a sample of 58 x 10(6) J/psi events collected 2 with the BESII detector, radiative decays J/psi --> gammagammaV, where V = rho or phi, are studied. A resonance around 1420 MeV/c(2) (X(1424)) is observed in the gammarho mass spectrum. Its mass and width are measured to be 1424 +/- 10(stat) +/- 11 (sys) MeV/c(2) and 101.0 +/- 8.8 +/- 8.8 MeV/c(2), respectively, and its branching ratio B(J/psi --> gammaX(1424) --> gammagammarho) is determined lobe (1.07 +/- 0.17 +/- 0.11) x 10(-4). A search for X(1424) --> gammaphi yields a 95% C.L. upper limit B(J/psi --> gammaX(1424) --> gammagammaphi) < 0.82 x 10(-4). (C) 2004 Elsevier B.V. All rights reserved.