Evidence is presented for a narrow state, called ξ, in the decay modes J/ψ→γξ, ξ→K+K−, and ξ→KS0KS0. In the K+K− mode, the ξ has a mass of 2.230±0.006±0.014 GeV/c2, a width of Γ=0.026−0.016+0.020± 0.017 GeV/c2, a product branching ratio of (4.2−1.4+1.7±0.8)×10 −5, and a statistical significance of ∼4.5 standard deviations. In the KS0KS0 mode, it has a mass of 2.232±0.007±0.007 GeV/c2, a width of Γ=0.018−0.015+0.023± 0.010 GeV/c2, a product branching ratio of (3.1−1.3+1.6±0.7)×10 −5, and a statistical significance of ∼3.6 standard deviations. Limits on ξ decay to other final states are presented.
No description provided.
Inelastic and elastic $J/\psi$ photoproduction on hydrogen are investigated at a mean energy of 105 GeV. The inelastic cross section with $E_{\psi} / E_{\gamma}$ < 0.9 is significantly lower than the corresponding result for muoproduction on iron targets, but is consistent with a second-order perturbative QCD calculation.
No description provided.
The production of J/ψ by π ± , K ± , p and p¯ incident on tungsten at 39.5GeV/ c beam momentum has been studied. Production of ψ' (3700) by π ± was also observed. The J/ψ relative particle/a ntiparticle cross-sections for x F 0 are σ(σ + ) σ(σ − =( are σ(σ ± )/σ(σ − )=(1.01±0.06), σ(K + )/σ(K) − )=(0.29±0.07) and σ(p) /σ(p¯)= (0.1+-0.03). The small p/p¯ and K + /K − cross-section ratios indicate the importance of valence quarks in the production process.
No description provided.
No description provided.
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No description provided.
J/ψ production on hydrogen and tungsten targets has been compared at 39.5 GeV/ c and the variation of the A -dependence of the J/ψ cross section as a function of p t 2 and x F has been measured. The A -dependence parameter, α, rises with increasing p t 2 and falls with increasing x F . Both effects are shown not to be due to the Fermi motion of nucleons in the tungsten nucleus.
No description provided.
No description provided.
The χ 1 ++ (3507) and the χ 2 ++ (3553) states have been observed in the Goliath spectrometer at the CERN SPS in 185 GeV/ c π − -Be collisions. Their radiative decays contribute 27.7% (for the χ 1 ++ ) and 12.8% (for the χ 2 ++ ) to J ϕ production. At this energy, their cross sections are 65±19 nb and 96±29 nb, respectively
No description provided.
We report on inclusive production of J ψ (3.1)-mesons observed in e + e − -annihilation in the energy range s = 4.0–5.0 GeV . After substraction of the radiative tail of the ψ(3.7) direct production of the J ψ (3.1) is found to be in the order of 0.1% of the total hadronic cross section. No enhancements are seen at s = 4.03 GeV and 4.4 GeV. The level is in agreement with expectations from violation of the Zweig-rule.
THIS IS 0.13 PCT OF THE TOTAL HADRONIC CROSS SECTION.
Virtual photoproduction of J/ ψ mesons has been measured for 280 GeV muon iron interactions in an iron/scintillator calorimeter target. The J/ψ's were identified by their decay into muon pairs. 315 events were observed, about half of which were elastic. The t , Q 2 and v distributions of these elastic events are presented. The v dependence is measured between 40 and 180 Mev and compared with lower energy photoproduction results. The Q 2 dependence is compared with the predictions of the vector dominance model.
TPRIME DISTRIBUTION OF ELASTIC J/PSI EVENTS FOR ALL Q2 AND NU WITH 280 GEV MUON BEAM.
NORMALIZED Q**2 DISTRIBUTION OF ELASTIC J/PSI EVENTS FOR ALL NU AND T WITH 280 GEV MUON BEAM.
EXTRAPOLATION OF Q**2 AND T DEPENDENCE TO CALCULATE D(SIG)/DT AT Q**2=0 AND T=0 FOR ELASTIC J/PSI PHOTOPRODUCTION PER NUCLEON.
The reactions e + e − → hadrons and e + e + e − →e + e − have been studied at the J/gY (3100) resonance). The relative weights of the topological cross sections for fixed charged multiplicity are σ 2 =(32±5)%, σ 4 =(49±8)%, σ 6 =(18±3)%, and σ 8 =(1±0.6)%. The average pion multiplicities are 〈 n ch 〉=3.8±0.3 and 〈n π o 〉=3.1±0.8 . The decay widths are Γ e =(4.6±0.8) keV, Γ h =(59±24) keV, and Γ =(68±26) keV.
CROSS SECTION AROUND RESONANCE.
CROSS SECTION JUST BELOW J/PSI.
MULTIPLICITY AT J/PSI.
A search has been made for the inclusive production of J ψ (3.1) and ϒ (9.4) mesons in e + e − interactions at 29 GeV, via their decay into two leptons. No signal is observed in the J ψ region, nor in the ϒ region. The limits on the cross sections are σ ( e + e − → ψX ) < 4.4 × 10 −36 cm 2 , and σ ( e + e − → ϒX ) < 4.7 × 10 −36 cm 2 . The same data yield limits on the branching ratios for the b quark BR ( b → ψX ) < 4.9% and BR ( b → ℓ + ℓ − X ) < 0.8%.
No description provided.
No description provided.
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