The decay channel J/ψ → γπ + π − η ′ is analyzed using a sample of 5.8 × 10 7 J/ψ events collected with the BESII detector. A resonance, the X(1835), is observed in the π + π − η ′ invariant mass spectrum with a statistical significance of 7.7σ. A fit with a Breit-Wigner function yields a mass M = 1833.7 ± 6.1(stat) ± 2.7(syst) MeV/c 2 , a width Γ = 67.7 ± 20.3(stat) ± 7.7(syst) MeV/c 2 and a

A new unitarization approach incorporated with chiral symmetry is established and applied to study the πK elastic scatterings. We demonstrate that the κ resonance exists, if the scattering length parameter in the I=1/2, J=0 channel does not deviate much from its value predicted by chiral perturbation theory. The mass and width of the κ resonance is found to be M κ = 594 ± 79M eV , Γ κ = 724 ± 332M eV , obtained by fitting the LASS data up to 1430MeV. Better determination to the pole parameters is possible if the chiral predictions on scattering lengths are taken into account.

The decays of J/psi --> etaphif(0)(980)[eta --> gammagamma, phi --> K(+) K(-), f(0)(980) --> pi(+)pi(-)] are analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector at the Beijing Electron-Positron Collider. A structure at around 2.18 GeV/c(2) with about 5 sigma significance is observed in the phif(0)(980) invariant mass spectrum. A fit with a Breit-Wigner function gives the peak mass and width of m = 2.186+/-0.010(stat)+/-0.006(syst) GeV/c(2) and Gamma = 0.065+/-0.023(stat)+/-0.017(syst) GeV/c(2), respectively, which are consistent with those of Y(2175), observed by the BABAR Collaboration in the initial-state radiation process e(+)e(-) --> gamma(ISR) phif(0)(980). The production branching ratio is determined to be Br(J/psi --> etaY(2175))Br(Y(2175)- -> phif(0)(980))Br(f(0)(980) --> pi(+)pi(-)) = [3.23+/-0.75(stat)+/-0.73(syst)] x 10(-4), assuming that the Y(2175) is a 1(--) state.

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Abstract. The decay J/ψ → ωpp is studied using a 5.8 × 10 7 J/ψ event sample accumulated with the BES II detector at the Beijing Electron-Positron Collider. The decay branching fraction is measured to be B(J/ψ → ωpp) = (9.8 ± 0.3 ± 1.4) × 10 −4 . No significant enhancement near the pp mass threshold is observed, and an upper limit of B(J/ψ → ωX(1860))B(X(1860) → pp) < 1.5 × 10 −5 is determined at the 95% confidence level, where X(1860) designates the near-threshold enhancement seen in the pp mass spectrum in J/ψ → γpp decays.

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