We have measured charged-particle production in neutron-nucleus collisions at high energy. Data on positive and negative particles produced in nuclei [ranging in atomic number (A) from beryllium to lead] are presented for essentially the full forward hemisphere of the center-of-mass system. A rough pion-proton separation is achieved for the positive spectra. Fits of the form Aα to the cross sections are presented as functions of transverse momentum, longitudinal momentum, rapidity, and pseudorapidity. It is found that α changes from ∼0.85 to ∼0.60 for laboratory rapidities ranging from 4 to 8. Trends in the data differ markedly when examined in terms of pseudorapidity rather than rapidity. Qualitatively, the major features of our data can be understood in terms of current particle-production models.
No description provided.
No description provided.
No description provided.
The production of the ϒ family in proton-nucleus collisions is clarified by a sixfold increase in statistics. Constraining ϒ,ϒ′ masses to those observed at DORIS we find the statistical significance of the ϒ′′ to be 11 standard deviations. The dependence of ϒ production on pt, y, and s is presented. Limits for other resonance production in the mass range 4-18 GeV are determined.
Cross section times branching ratio.
No description provided.
The inclusive production of ϱ 0 mesons in pp collisions has been measured at five c.m. energies from √ s = 23.6 to 63.0 GeV. The cross sections and the production spectra as a function of transverse momentum and rapidity are discussed.
No description provided.
No description provided.
We present proton-nucleus dimuon-production cross sections for masses between 4 and 15 GeV, center-of-mass rapidities between -0.23 and 0.6 and incident energies of 200, 300, and 400 GeV. The data confirm scaling to the 20% level. The dependence of continuum 〈pT〉 on beam energy is also presented.
No description provided.
No description provided.
No description provided.
The mass spectrum of muon pairs in the range 5 to 15 GeV is studied in the inclusive reaction p+nucleus→μ++μ−+anything. The ϒ and continuum distribution are presented as is the A dependence of the continuum. Comparison with a parton-annihilation model yields a sea-quark distribution.
No description provided.
No description provided.
Dimuon production is studied in 400-GeV proton-nucleus collisions. A strong enhancement is observed at 9.5 GeV mass in a sample of 9000 dimuon events with a mass $m_{\mu^+\mu^-} \to$ 5 GeV.
Two peaks were observed. Mass spectrum was fitted to one and two resonance hypothesis.
Inclusive K ∗0 production is studied in π − p interactions at 16 GeV/ c with x ϝ > 0.2. The K ∗0 is found to be pre-dominantly centrally produced with cross section σ( K ∗0 ) = (72 ± 12) μb for x ϝ > 0.2 and compares closely to data on K ∗0 production in π + p interactions at the same energy.
No description provided.
No description provided.
No description provided.
Results on K 0 and Λ production in p↑p interactions at 6 GeV are presented. The data are from an exposure of the Argonne 12 ft bubble chamber to a 60% transversely polarized proton beam. Results include data on Λ and K 0 inclusive production, and on the reactions p↑p → p Λ K + (p Σ 0 K + ). The beam asymmetry parameter for p ↑ p → K 0 ( K 0 ) + X is determined to be (−0.52 ± 0.12).
No description provided.
The inclusive spectra for p p collisions at 22.4 GeV/ c are investigated. We show that the transverse momentum distributions resemble those in high-energy pp interactions and discuss the influence of annihilation processes on the p T 2 distributions. The invariant inclusive cross section for pions in the central region is found to be 28 ± 1 mb. A charge asymmetry is indicated by the y ∗ spectrum in the central region, the asymmetry parameter having the value 0.15 ± 0.01. Finally, we estimate the upper limit of the diffraction dissociation of the beam particle to be 3.68 −0.15 +0.45 mb.
No description provided.
No description provided.
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.
Forum