The spin asymmetryAN for inclusive π0 production by 200-GeV transversely-polarized protons on a liquid hydrogen target has been measured at Fermilab over a wide range ofxF, with 0.5<pT<2 GeV/c. AtxF>0.3, the asymmetry rises with increasingxF and reaches a value ofAN=0.15±0.03 in the region 0.6<xF<0.8. This result provides new input regarding the question of the internal spin structure of transversely-polarized protons.
No description provided.
False asymmetry calculated for events with average beam polarization of zero.
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The analyzing power AN of proton-proton elastic scattering in the Coulomb-nuclear interference region has been measured using the 200-GeV/c Fermilab polarized proton beam. A theoretically predicted interference between the hadronic non-spin-flip amplitude and the electromagnetic spin-flip amplitude is shown for the first time to be present at high energies in the region of 1.5 × 10−3 to 5.0 × 10−2 (GeV/c)2 four-momentum transfer squared, and our results are analyzed in connection with theoretical calculations. In addition, the role of possible contributions of the hadronic spin-flip amplitude is discussed.
No description provided.
The highest-energy measurement of ΔσL(pp) and the first ever measurement of ΔσL(p¯p), the differences between proton-proton and antiproton-proton total cross sections for pure longitudinal spin states, are described. Data were taken using 200-GeV/c polarized beams incident on a polarized-proton target. The results are measured to be ΔσL(pp)=−42±48(stat)±53(syst) μb and ΔσL(p¯p)=−256±124(stat)±109(syst) μb. Many tests of systematic effects were investigated and are described, and a comparison to theoretical predictions is also given. Measurements of parity nonconservation at 200 GeV/c in proton scattering and the first ever of antiproton scattering have also been derived from these data. The values are consistent with zero at the 10−5 level.
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The analyzing power A N of proton-proton, proton-hydrocarbon, and antiproton-hydrocarbon, scattering in the Coulomb-nuclear interference region has been measured using thhe 185 GeV/ c Fermilab polarized-proton and -antiproton beams. The results are found to be consistent with theoretical predictions within statistical uncertainties.
No description provided.
Data from hydrocarbon target.
Data from hydrocarbon target.
In an experiment performed at Fermilab we have studied the production of high p t hadron jets from 400 GeV/ c pp interactions. A large solid-angle, towered calorimeter was used to trigger and reconstruct the jet events. We report results for inclusive single-jet production and compare those results with QCD predictions and results obtained at the ISR and the SPS Collider.
The invariant distribution is fitted to CONST*(1/PT**POWER)*(1-XT)**POWER.
An experiment performed at Fermilab used double-arm calorimeter triggers to study di-jet production by 400 GeV protons and 200 GeVπ− mesons incident on liquid hydrogen. The observed ratio of positive to negative leading particles in the jets was compared forpp andπp production using a tree level parton scattering model. The results are moderately sensitive to the form of the pion gluon distribution function and yieldx g(x)⋍(1−x)2.75±0.40±0.75.
One parameter function is used for gluon distribution: X*G(X) = C*(1-x)**POWER.
The coherent production of π and ρ mesons in νμ (ν¯μ)-neon charged-current interactions has been studied using the Fermilab 15-foot bubble chamber filled with a heavy Ne-H2 mix and exposed to the Tevatron quadrupole triplet (anti)neutrino beam. The νμ (ν¯μ) beam had an average energy of 80 GeV (70 GeV). From a sample corresponding to approximately 28 000 charged-current interactions, net signals of (53±9) μ±π∓ coherent events and (19±7) μ±π∓π0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2±0.7)×10−38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1±0.8)×10−38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at |t|<0.1 GeV2 are found to be in general agreement with the predictions of a model based on the hadron dominance and, in the pion case, on the partially conserved axial-vector current hypothesis. Also discussed is the coherent production of systems consisting of three pions.
No description provided.
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The Fermilab 15-ft bubble chamber has been exposed to a quadrupole triplet neutrino beam produced at the Tevatron. The ratio of ν to ν¯ in the beam is approximately 2.5. The mean event energy for ν-induced charged-current events is 150 GeV, and for ν¯-induced charged-current events it is 110 GeV. A total of 64 dimuon candidates (1 μ+μ+, 52 μ−μ+ and μ+μ−, and 11 μ−μ−) is observed in the data sample of approximately 13 300 charged-current events. The number and properties of the μ−μ− and μ+μ+ candidates are consistent with their being produced by background processes, the important sources being π and K decay and punchthrough. The 90%-C.L. upper limit for μ−μ−/μ− for muon momenta above 4 GeV/c is 1.2×10−3, and for momenta above 9 GeV/c this limit is 1.1×10−3. The opposite-sign-dimuon–to–single-muon ratio is (0.62±0.13)% for muon momenta above 4 GeV/c. There are eight neutral strange particles in the opposite-sign sample, leading to a rate per dimuon event of 0.65±0.29. The opposite-sign-dimuon sample is consistent with the hypothesis of charm production and decay.
No description provided.
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Charged vector D*+(2010) meson production is studied in a high energy neutrino bubble chamber experiment with mean neutrino energy of 141 GeV. The D*+ are produced in (5.6±1.8)% of the neutrino charged current interactions, indicating a steep increase of cross section with energy. The mean fractional hadronic energy of the D*+ meson is 0.55 ± 0.06.
No description provided.
The ratio of cross sections for inelastic muon scattering on xenon and deuterium nuclei was measured at very low Bjorken x (0.000 02<xBj<0.25). The data were taken at Fermilab experiment E-665 with a 490 GeV/c muon beam incident on liquid deuterium and gaseous xenon targets. Two largely independent analysis techniques gave statistically consistent results. The xenon-to-deterium per-nucleon cross-section ratio is constant at approximately 0.7 for xBj below 0.003.
Data using Electromagnetic Cuts.
Data using Hadron Requirement.
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