P. Lang

activity

19982000

collaborators

5 papers

hep-ex2000

A Measurement of the Mass and Full-Width of the $η_{c}$ Meson

J. Z. Bai

In a sample of 7.8 million $J / ψ$ decays collected in the Beijing Spectrometer, the process J/ $ψ \to γ η_{c}$ is observed for five different $η_{c}$ decay channels: $K^{+} K^{-} π^{+} π^{-}$ , $π^+π^-…

hep-ex1999

Measurement of the Total Cross Section for Hadronic Production by e+e- Annihilation at Energies between 2.6-5 Gev

J. Z. Bai

Using the upgraded Beijing Spectrometer (BESII), we have measured the total cross section for $e^{+} e^{-}$ annihilation into hadronic final states at center-of-mass energies of 2.6, 3.…

hep-ex1998

Study of the Hadronic Decays of χ_c States

J. Z. Bai

Hadronic decays of the P-wave spin-triplet charmonium states χ_cJ (J=0,1,2) are studied using a sample of ψ(2S) decays collected by the BES detector operating at the BEPC storage r…

hep-ex1998

Determination of the J/psi Leptonic Branching Fraction via psi(2S) -> pi^+ pi^- J/psi

J. Z. Bai

A comparison of the rates for psi(2S) -> pi^+ pi^- J/psi, J/psi -> l^+l^- and J/psi -> anything is used to determine the J/psi leptonic branching fractions. The results are B(J/psi…

hep-ex1998

Branching Fractions for $ψ (2 S) t o γ η^{'}$ and $γ η$

J. Z. Bai

We report the first measurements of the branching fractions: $B (ψ (2 S) - > γ η^{'}) = (1.54 \pm 0.31 \pm 0.23) x 1 0^{- 4}$ and $B (ψ (2 S) - > γ η) = (0.53 \pm 0.31 \pm 0.08) x 1 0^{- 4}$ . The $…

A Measurement of the Mass and Full-Width of the ηc​ Meson

Measurement of the Total Cross Section for Hadronic Production by e+e- Annihilation at Energies between 2.6-5 Gev

Study of the Hadronic Decays of χ_c States

Determination of the J/psi Leptonic Branching Fraction via psi(2S) -> pi^+ pi^- J/psi

Branching Fractions for ψ(2S)toγη′ and γη

A Measurement of the Mass and Full-Width of the $η_{c}$ Meson

Branching Fractions for $ψ (2 S) t o γ η^{'}$ and $γ η$