The production of ψ(3.1) mesons is reported for the reactions π−+Fe→μ++μ−+anything, at 200 GeV, and p+Fe→μ++μ−+anything, at 240 GeV. For ψ production, distributions in x≡PLPbeam and P⊥ are given. For x>~0.5, the ratio of the ψ production cross sections in iron for pions to that for protons is found to be 7.4±2.0.
No description provided.
No description provided.
CDB=THESE DATA TO BE MULTIPLIED BY FACTOR 10.0.
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.
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.
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 present results of a large-acceptance experiment in which muon pairs were observed in the mass range 0.6 to 6.0 GeV/c2. Emphasis is given to features of the production of Jψ and ψ′(3.7) particles. We find [Bσ]ψ′(3.7)[Bσ]Jψ to be 0.007±0.004 for p-C and 0.018±0.007 for π+-C interactions. Comparison with results from e+e− storage rings indicates that both the Jψ and the ψ′(3.7) are produced strongly rather than electromagnetically in our experiment.
No description provided.
We report measurements at the CERN PS of the production cross section of J/ψ(3.1) by 24 GeV protons on hydrogen, carbon, and tungsten.
No description provided.
ASSUME B.R.(E+E-) =0.069.
Results are presented from an experiment with a large acceptance spectrometer that measured the production cross section of high mass muon pairs from the collision of 225 GeV/c hadron beams with a nuclear target including, for the first time, measurements using positive and negative pion beams. Various features of the data, such as the helicity anqle of the muon pairs and the ratio of the cross sections for positive and negative pions provide conclusive evidence for the quark-antiquark annihilation model for the production of muon pairs. This model is then used to determine the momentum distribution for valence quarks in pion. our best fit to the distribution,$\bar{\mu} (x) = (.73 \pm .11) x^{-1/2} [1-x] ^{(1.28 \pm .15)}$ , shows that the pion's structure! is clearly different from the proton's structure.
DATA ON (E/2*PI*PMAX(RF=CM))*D2(SIG)/D(XL)/D(PT)/PT WHERE THE CENTER OF MASS DEFINITION OF THE XL ASSUMED THAT THE TARGET WAS A SINGLE NUCLEON OF MASS 0.938 GEV. Axis error includes +- 0.0/0.0 contribution (?////SYSTEMATIC ERRORS NOT GIVENFERMI//COULOMBRES-DEF(RES=J/PSI,BACK=UNCORRECTED,DEF=2.7 < M(MU+ MU-) IN GEV < 3.5)).
DATA ON (E/2*PI*PMAX(RF=CM))*D2(SIG)/D(XL)/D(PT)/PT WHERE THE CENTER OF MASS DEFINITION OF THE XL ASSUMED THAT THE TARGET WAS A SINGLE NUCLEON OF MASS 0.938 GEV. Axis error includes +- 0.0/0.0 contribution (?////SYSTEMATIC ERRORS NOT GIVENFERMI//COULOMBRES-DEF(RES=J/PSI,BACK=UNCORRECTED,DEF=2.7 < M(MU+ MU-) IN GEV < 3.5)).
DATA ON (E/2*PI*PMAX(RF=CM))*D2(SIG)/D(XL)/D(PT)/PT WHERE THE CENTER OF MASS DEFINITION OF THE XL ASSUMED THAT THE TARGET WAS A SINGLE NUCLEON OF MASS 0.938 GEV. Axis error includes +- 0.0/0.0 contribution (?////SYSTEMATIC ERRORS NOT GIVENFERMI//COULOMBRES-DEF(RES=J/PSI,BACK=UNCORRECTED,DEF=2.7 < M(MU+ MU-) IN GEV < 3.5)).
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.
A detailed study ofJ/ψ hadronic production has been performed in a high statistics experiment (more than 1.5 106J/ψ observed in their dimuon decay mode). Data have been taken with incident π±,K±,p±, on hydrogen and platinum targets, at 150, 200 and 280 GeV/c. We find from the observed nuclear dependance of the cross sections, that about 18% of theJ/ψ are produced diffractively. Using known structure functions of the quarks in the nucleon and in the pion, we derive estimations for the gluon structure functions.
No description provided.
No description provided.
No description provided.
The yield of J/ψ and ψ’ vector-meson states has been measured for 800-GeV protons incident on deuterium, carbon, calcium, iron, and tungsten targets. A depletion of the yield per nucleon from heavy nuclei is observed for both J/ψ and ψ’ production. This depletion exhibits a strong dependence on xF and pt. Within experimental errors the depletion is the same for the J/ψ and the ψ’.
Ratio of heavy nucleus to deuterium yields. A is the mass number of the target nucleus.
Ratio of heavy nucleus to deuterium yeilds. A is the mass number of the target nucleus.
Ratio of heavy nucleus to deuterium yeilds. A is the mass number of the target nucleus.
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