We present data on the reaction ν p → μ + pπ − from an exposure of the Fermilab 15 ft hydrogen bubble chamber. The channel cross section for 5 GeV < E ν < 70 GeV and M( p π − ) < 1.9 GeV is σ = (27 ± 5) × 10 −40 cm 2 . This cross section is dominated by the I = 1 2 production amplitude.
No description provided.
The inclusive production of Λ , K S 0 , Σ ± (1385) and K ∗± (892) in π − p interactions at 6 GeV/ c has been studied. The observed cross sections are: σ ( Λ )=0.94±0.06 mb, σ (K S 0 )=0.98±0.06 mb, σ ( Σ + (1385))=60±7 μb , σ ( Σ − (1385))=90±9 μ b, σ( K ∗+ (892))=216±28 μ b and σ( K ∗− (892))=41±8 μ b , respectively. The inclusive spectra of these particles are presented as functions of squared transverse momentum and Feynman scaling variable x . The polarization of Λ has also been investigated. It is found from a comparison with higher-energy data that the inclusive cross sections for Σ ± (1385) and the production ratios Σ ± (1385)/ Λ in π − p at 6 GeV/ c have not reached the high-energy limiting values.
No description provided.
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Average total cross sections are given for neutrino charged current interactions at neutrino energies of 2.87 GeV and 9.05 GeV. The ratios 〈σ〉 〈E〉 are 0.69 ± 0.05 and 0.61 ± 0.06 in units of 10 −38 cm 2 /GeV nucleon, respectively The errors include both statistical and systematic uncertainties.
Measured charged current total cross section.
Measured charged current total cross section.
The cross section for the K L 0 p elastic scattering has been measured for the first time. The incident momentum and momentum transfer ranges are 3 ⩽ p ⩽ 13 GeV/ c , 0.1 ⩽ | t | ⩽ 1.3 GeV 2 . The results are compared to those of other experiments related to ours by isotopic spin conservation, finding agreement with some and discrepancies with others. The differential cross sections have been parametrized in the form A e bt . The coefficients show little or no dependence on energy, with A ≅ 9.8 mb · GeV −2 and b ≅ 4.7 GeV −2 . The effective linear trajectory has been determined and gives α 0 = 0.95 ± 0.15, α ′ = −0.35 ± 0.48 GeV −2 , in good agreement with dominance by pomeron exchange.
CROSS SECTIONS DEDUCED FROM THE 46 PCT OF EVENTS WHICH YIELD UNIQUE SOLUTIONS.
<RAW> CROSS SECTIONS DEDUCED FROM A STATISTICAL TREATMENT OF ALL EVENTS.
<SMOOTHED> CROSS SECTIONS DEDUCED FROM A STATISTICAL TREATMENT OF ALL EVENTS.
The differential cross sections for γp→γp and γp→π0p have been measured for incident photon energies in the range of 2 to 6 GeV and for |t| ranging from 0.7 to 4.3 GeV2. This corresponds to a center-of-mass angle range of 45° to 128°. The energy dependence of the data is compared to that predicted by several parton models.
No description provided.
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The polarization in π + p → π + p and K + p → K + p has been measured at 6 and 12 GeV/ c in the four-momentum transfer interval 0.1 ⩽ | t | ⩽ 2.0 (GeV/ c ) 2 by scattering on protons of a polarized deuteron target. Comparison with existing results obtained with polarized proton targets shows good general agreement and no evidence for asymmetry effects due to the presence of the spectator neutron. For K + p elastic scattering polarization the experiment yields improved statistics, especially at 6 GeV/ c
No description provided.
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We have observed the D(1285), E(1420) and δ(975) mesons produced in 12 and 15 GeV/ c π − p interactions at the CERN Omega Spectrometer. Production cross sections and decay branching ratios are presented. Analysis of the decay D(1285) → δ (975) π favours a spin-parity assignment of 1 + .
No description provided.
CORRECTED FOR DECAY MODES OTHER THAN <ETA PI+ PI-> AND FOR THE UNOBSERVED PARTS OF THE T-DISTRIBUTION.
No description provided.
We have extended our survey of the reaction γ+p→p+e++e− by collecting 20 000 additional e+e− pairs in the invariant-mass region 900<m<1500 MeV. The measured interference pattern shows two enhancements at mass values of 1097 and 1266 MeV. The parameters of those structure, when interpreted as vector mesons in the VDM framework, are given.
No description provided.
From a muon-proton scattering experiment with a streamer chamber at the Stanford Linear Accelerator we present results in the ranges 0.3<Q2<4.7 GeV2 and 1.7<W<4.7 GeV for the reactions μ+p→μpV where V is a vector meson (ρ0, ω, or φ). It is shown that in ρ production the skewing parameter and the longitudinal-transverse ratio change significantly as Q2 increases above 1 GeV2. The cross section for ρ0 production as a function of Q2 falls below the vector-meson-dominance prediction. The ratio of the cross section for exclusive vector-meson production to the total cross section falls by a factor of 10 between photoproduction and a Q2 of 2 GeV2, yet the ratio of ω to ρ production remains constant at the photoproduction value out to Q2>2 GeV2.
THE ABSOLUTE TOTAL CROSS SECTION IS FROM A FIT TO THE MIT-SLAC ELECTRON SCATTERING DATA BY W. ATWOOD AND S. STEIN.
No description provided.
FOR 0.6 < M(PI+ PI-) < 0.9 GEV, USING THE METHOD OF MOMENTS.
We present experimental data on the K L 0 p → K S 0 p reaction between 4 and 14 GeV/ c in the range 0.1 ≲ | t | ≲ 2 GeV 2 . This experiment has been performed at the CERN PS, using spark chambers and a large aperture magnet. The results show a break of slope at t = −0.3 GeV 2 . The ω trajectory deduced from the data has an intercept α (0) = 0.5 and a slope α ′ = 0.88. A comparison with various models shows that the non-flip amplitude is dominant.
No description provided.
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