We present results from the initial run of Fermilab experiment E706. The data include incident π− and p beams at 500 GeV/c on Be and Cu targets, and span the kinematic ranges of transverse momentum and rapidity of 3.5≤pT≤10 GeV/c and −0.7≤yc.m.≤0.7, respectively. We have measured cross sections for π0 and direct-photon production, as well as the ηπ0 production ratio. From the data on Be and Cu, we have extracted the nuclear dependence of π0 production, parametrized as Aα. The cross sections are compared with next-to-leading-log QCD predictions for different choices of the QCD momentum scales and several sets of parton distribution functions.
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No description provided.
Backward elastic K<sup loc="post">+</sup>p and K<sup loc="post">−</sup>p scattering has been measured in the angular interval 168<sup loc="post">o</sup> <θc.m. < 177<sup loc="post">o</sup>. We find <math altimg="si1.gif">(<rm>d</rm>σ/<rm>d</rm>Ω) <inf loc="post"><rm>K</rm><sup loc="post">+</sup><rm>p</rm> → <rm>pK</rm><sup loc="post">+</sup></inf> = 17 ± 4 μ<rm>b</rm>/<rm>sr</rm></math> and <math altimg="si2.gif">(<rm>d</rm>σ/<rm>d</rm>Ω)<inf loc="post"><rm>K</rm><sup loc="post">−</sup><rm>p</rm> → <rm>pK</rm><sup loc="post">−</sup></inf> < 0.6 μ<rm>b</rm>/<rm>sr</rm></math>. K<sup loc="post">+</sup>p elastic scattering exhibits a backward peak.
The data for cos(theta) = 1 is the extrapolation.
The data for cos(theta) = 1 is the extrapolation.
We report new measurements of inclusive direct photon production at high transverse momenta (pT) for π− and p interactions on Be at 500 GeV/c. The yields as a function of pT and rapidity (y) are in good agreement with expectations from next-to-leading-log QCD calculations employing recently extracted quark and gluon structure functions.
We present results of measurements of the differential cross sections for the following elastic-scattering reactions: (i) π + p at 5.2 and 7.0 GeV/ c in the range −1 < u < 0.02 (GeV/ c ) 2 , (ii) π − p at 7.0 GeV/ c in the range −0.7 < u < 0.05 (GeV/ c ) 2 , (iii) K + p at 5.2 and 7.0 GeV/ c in the ranges −1 < t < −0.01 (GeV/ c ) 2 and −1 < u < 0 (GeV/ c ) 2 , and K − p at 7.0 GeV/ c in the range −1 < u < 0 (GeV/ c ) 2 .
No description provided.
No description provided.
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Data are presented on elastic πp and Kp scattering for values of −t up to 2.5 and 3.5 (GeV/c)2 at incident momenta of 100 and 200 GeV/c, respectively. All of the cross sections are found to be nearly identical, although there is some momentum dependence of the π+p data; a small systematic difference observed between pion and kaon data cannot be explained by geometrical scaling.
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The angular distributions of K<sup loc="post">+</sup>p and π<sup loc="post">+</sup>p backward elastic scattering have been measured at 5.2 and 6.9 GeV/c. Backward π<sup loc="post">-</sup>p and K<sup loc="post">-</sup>p elastic scattering were studied at 6.9 GeV/c. Backward peaks are observed in K<sup loc="post">+</sup>p scattering with an energy dependence of the form s<sup loc="post">−4</sup>.
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We present new measurements of π0 production at high transverse momenta (pT) for π− and p interactions on Be and Cu targets at 500 GeV/c. The observed dependence of the yields as a function of pT and rapidity (y) is compared with expectations from leading-log QCD over a kinematic range in which the inclusive cross sections fall by more than 4 order of magnitude.
Results are presented on π±p, K±p, and p±p elastic scattering measured with an apparatus having acceptance of 0.5<−t<2.5 (GeV/c)2 and 0.9<−t<11 (GeV/c)2 at 100 and 200 GeV/c, respectively. A diffractionlike dip is seen for the first time in the π−p t distribution at −t=4 (GeV/c)2. All meson-proton cross sections are found to be similar in the range 1<−t<2.5 (GeV/c)2, although some small systematic differences are observed. Cross sections for pp and p―p are compared with previous data.
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We have studied single diffraction dissociation ( p p→ p X ) in proton-antiproton collisions at √ s =1.8TeV, covering the ranges 3⪅ M X ⪅200 GeV and 0.05⪅| t |⪅0.11 (GeV/ c ) 2 . Parameterizing the production to be of the form dσ ( d t d M 2 X ) = (M 2 X ) −α exp (bt) , we obtain α = 1.13±0.07 and b = 10.5±1.8(GeV/ c ) −2 . The total single diffraction dissociation cross section is 2 σ SD =8.1±1.7 mb. Comparisons are made to previous lower energy data, and to an earlier measurement by us at the same energy.
New measurements are reported of total cross sections for π ± , K ± , p and p on protons and deuterons at 11 momenta between 23 and 280 GeV/ c .
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