Limit on the anti-d / anti-u asymmetry of the nucleon sea from Drell-Yan production

McGaughey, P.L. ; Moss, J.M. ; Alde, D.M. ; et al.
Phys.Rev.Lett. 69 (1992) 1726-1728, 1992.
Inspire Record 344919 DOI 10.17182/hepdata.19848

We present an analysis of 800-GeV proton-induced Drell-Yan production data from isoscalar targets 2H and C, and from W, which has a large neutron excess. The ratio of cross sections per nucleon, R-σW/σIS, is sensitive to the difference between the d¯(x) and u¯(x) structure functions of the proton. We find that R is close to unity in the range 0.04≤x≤0.27, allowing upper limits to be set on the d¯-u¯ asymmetry. Additionally, the shape of the differential cross section m3 d2σ/dxF dm for 2H at xF≊0 shows no evidence of an asymmetric sea in the proton. We examine the implications of these data for various models of the violation of the Gottfried sum rule in deep-inelastic lepton scattering.

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Nuclear Dependence of Dimuon Production at 800-GeV

Alde, D.M. ; Baer, H.W. ; Carey, T.A. ; et al.
Phys.Rev.Lett. 64 (1990) 2479-2482, 1990.
Inspire Record 303588 DOI 10.17182/hepdata.19997

A precise measurement of the atomic-mass dependence of dimuon production induced by 800-GeV protons is reported. Over 450 000 muon pairs with dimuon mass M≥4 GeV were recorded from targets of H2, C, Ca, Fe, and W. The ratio of dimuon yield per nucleon for nuclei versus H2, R=YA/Y2H, is sensitive to modifications of the antiquark sea in nuclei. No nuclear dependence of this ratio is observed over the range of target-quark momentum fraction 0.1<xt<0.3. For xt<0.1 the ratio is slightly less than unity for the heavy nuclei. These results are compared with predictions of models of the European Muon Collaboration effect.

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Nuclear dependence of the production of Upsilon resonances at 800-GeV

Alde, D.M. ; Baer, H.W. ; Carey, T.A. ; et al.
Phys.Rev.Lett. 66 (1991) 2285-2288, 1991.
Inspire Record 315062 DOI 10.17182/hepdata.19910

The yields of the 1S and the sum of the 2S and 3S Υ resonances have been measured for 800-GeV protons incident on targets of H2, C, Ca, Fe, and W. A significant nuclear dependence is seen in the yield per nucleon which, within errors, is the same for the Υ(1S) and Υ(2S+3D) states. A large decrease in the relative yield from heavy nuclei is found for the range xF<0. Significant nuclear dependence is also observed in the pt distribution. Differential cross sections for the Υ(1S) for H2 are presented over the ranges 0.24≤pt≤3.4 GeV/c and -0.15≤xF≤0.5.

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The A-Dependence of $J / \psi$ and $\psi^{\prime}$ Production at 800 GeV/c

Alde, D.M. ; Baer, H.W. ; Carey, T.A. ; et al.
Phys.Rev.Lett. 66 (1991) 133-136, 1991.
Inspire Record 301531 DOI 10.17182/hepdata.19916

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’.

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Nuclear dependence of neutral D meson production by 800-GeV/c protons

The E789 collaboration Leitch, M.J. ; Boissevain, J. ; Carey, T.A. ; et al.
Phys.Rev.Lett. 72 (1994) 2542-2545, 1994.
Inspire Record 371874 DOI 10.17182/hepdata.19694

The nuclear dependence for 800 GeV/c proton production of neutron D mesons has been measured near xF=0 in Experiment 789 at Fermilab. D mesons from beryllium and gold targets were detected with a pair spectrometer and a silicon vertex detector via their decay D→Kπ. No nuclear dependence is found, with a measured α=1.02±0.03±0.02. The measured differential cross section, dσ/dxF, for neutral-D-meson production at 〈xF〉=0.031 is 58±3±7 μb/nucleon. The integrated cross section obtained by extrapolation of the measured cross section to all xF is 17.7±0.9±3.4 μb/nucleon and is consistent with previous measurements.

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Production of J / psi at large x(F) in 800-GeV/c p copper and p beryllium collisions

Kowitt, M.S. ; Gidal, G. ; Ho, P.M. ; et al.
Phys.Rev.Lett. 72 (1994) 1318-1321, 1994.
Inspire Record 361036 DOI 10.17182/hepdata.42472

The differential cross sections dσ/dxF for J/ψ produced inclusively in 800 GeV/c p-Cu and p-Be collisions have been measured in the kinematic range 0.30≤xF≤0.95 through the decay mode J/ψ→μ+μ−. They are compared with the predictions of the semilocal duality model for several sets of parton density functions. No evidence for a suggested intrinsic charm contribution to the cross section is observed. The ratio of the differential cross sections for Cu and Be targets confirms the suppression of J/ψ production in heavy nuclei at large xF.

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A Measurement of the Neutral Current Electroweak Parameters using the Fermilab Narrow Band Neutrino Beam

Reutens, P.G. ; Merritt, F.S. ; Oreglia, M.J. ; et al.
Z.Phys.C 45 (1990) 539-550, 1990.
Inspire Record 305243 DOI 10.17182/hepdata.15280

We report a measurement of the electroweak parameters sin2θw and ϱ based on the ratios of neutral current to charged current events measured in the Fermilab narrow-band neutrino beam at energies of 30–240 GeV. The data are fully corrected for radiative effects, heavy-quark production, and other effects. The best value for sin2θw obtained, sin2θw=0.239±0.011, is consistent with the most recent values fromW andZ production, as well as from other neutrino experiments.

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A Measurement of $\Lambda_{\overline{MS}}$ from $\nu_{\mu}$ - Fe Nonsinglet Structure Functions at the Fermilab Tevatron

Quintas, P.Z. ; Leung, W.C. ; Mishra, S.R. ; et al.
Phys.Rev.Lett. 71 (1993) 1307-1310, 1993.
Inspire Record 336860 DOI 10.17182/hepdata.19733

The CCFR Collaboration presents a measurement of scaling violations of the nonsinglet structure function and a comparison to the predictions of perturbative QCD. The value of ΛQCD, from the nonsinglet evolution with Q2>15 GeV2 and in the modified minimal-subtraction renormalization scheme, is found to be 210±28(stat)±41(syst) MeV.

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Neutrino Production of Same Sign Dimuons

Schumm, B.A. ; Merritt, F.S. ; Oreglia, M.J. ; et al.
Phys.Rev.Lett. 60 (1988) 1618, 1988.
Inspire Record 23079 DOI 10.17182/hepdata.20157

In a sample of 670 000 charged-current neutrino events, 101 μ−μ− events have been observed, with 30 GeV<Eν<600 GeV and Pμ>9 GeV/c for both muons. After background subtraction, 18.5±13.9 events remain, yielding a prompt rate of (5.5±4.1)×10−5 per charged-current event. A sample of 124 000 antineutrino events yields 15 μ+μ+ events, giving 6.4±4.2 events after background subtraction and a prompt rate of (1.0±0.7)×10−4 per charged-current event. The numbers and kinematic distributions of these events are consistent with standard model sources.

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Measurement of Beauty Hadron Pair Production in 600-GeV/c $\pi^-$ Emulsion Interactions.

The Fermilab E653 collaboration Kodama, K. ; Ushida, N. ; Mokhtarani, A. ; et al.
Phys.Lett.B 303 (1993) 359-367, 1993.
Inspire Record 363168 DOI 10.17182/hepdata.28925

We report on the production characteristics and total cross section for 9 beauty hadron pairs produced by a 600 GeV/ c π − beam, the first such information in this energy region. The events were detected in the hybrid emulsion spectrometer of Fermilab Experiment E653. The measured pair cross section for all χ F , assuming linear A dependence, is 33±11 (stat.)±6(syst.) nb/nucleon. Fits of the inclusive single-hadron production distribution to the forms d σ d χ F ∝ (1−|χ F −χ 0 |) n and d σ d p T 2 ∝ exp (−bp t 2 ) give n=5.0 −2.1−1.7 +2.7+1.7 , χ 0 =0.06 −0.07−0.03 +0.06+0.02 , and b=0.13 −0.04−0.02 +0.05+0.02 ( GeV /c −2 . .The pairs tend to be produced back-to-back.

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