We report on the production of J/psi mesons in 530 and 800 GeV/c proton - Be collisions in the Feynman-x range 0.0 < xf < 0.6. The J/psi mesons were detected via decays into opposite sign muon pairs. Differential distributions for J/psi production have been measured as functions of xf, pT^2, and cosine of the Gottfried-Jackson decay angle. These distributions are compared with results on J/psi production obtained in 515 GeV/c pion - Be collisions, measured by the same experiment, as well as with results from other experiments using incident protons.
Differential XL distribution for J/PSI production in 530 GeV pBe collisions. Errors are combined statistics and systematics.
Differential PT**2 distribution for J/PSI production in 530 GeV pBe collisions. Errors are combined statistics and systematics.
Differential COS(THETA) distribution for J/PSI production in 530 GeV pBe collisions. Errors are combined statistics and systematics.
The differential cross sections dσ/dxF for J/ψ produced inclusively in 800 GeV/c p-Cu and p-Be collisions have been measured in the kinematic range 0.30≤xF≤0.95 through the decay mode J/ψ→μ+μ−. They are compared with the predictions of the semilocal duality model for several sets of parton density functions. No evidence for a suggested intrinsic charm contribution to the cross section is observed. The ratio of the differential cross sections for Cu and Be targets confirms the suppression of J/ψ production in heavy nuclei at large xF.
No description provided.
No description provided.
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Data is extrapolated to full x range.
Data requested from authors.
We report the measurements of the inclusive μ-pair production by 150-GeV protons and π+ mesons on beryllium. Absolute cross sections as well as the Feynman-x and PT dependence are presented in the mass region between 0.211 and 3.5 GeV/c2. Upper limits are also given for the inclusive production of η and ρ′(1600) mesons.
DATA OBTAINED FROM FIGURE BY A.A. LEBEDEV.
DATA OBTAINED FROM FIGURE BY A.A. LEBEDEV.
No description provided.
We report preliminary results on the production of electron-positron pairs in the mass range 2.5 to 4 GeV in 400-GeV p-Be interactions. Production cross sections of the ψ(3100) near x=0 as a function of pt, x, and the decay angle are presented and implications of these new data for single direct leptons are discussed. A ψ′(3700) signal is observed at a level corresponding to σ(ψ′)σ(ψ)=(10±3)%.
No description provided.
Invariant mass spectrum of μ + μ − pairs produced by 70 GeV/ c protons in Be target are presented. Distinct enhancements in the mass regions of ϱ, ω mesons, φ meson and J/ψ particle are observed. For J/ψ production x and p ⊥ 2 distributions are given. The total cross section for the reaction p + Be → ( J ψ → μ + μ − ) + … is equal to 9.5 ± 2.5 nb/nucleus .
No description provided.
ASSUME B.R.(MU+MU-) = 0.069.
ASSUME A**(2/3) DEPENDENCE FOR SIGMA.