Parton energy loss limits and shadowing in Drell-Yan dimuon production.

The NuSea collaboration Vasilev, M.A. ; Beddo, M.E. ; Brown, C.N. ; et al.
Phys.Rev.Lett. 83 (1999) 2304-2307, 1999.
Inspire Record 501230 DOI 10.17182/hepdata.19445

A precise measurement of the ratios of the Drell-Yan cross section per nucleon for an 800 GeV/c proton beam incident on Be, Fe and W targets is reported. The behavior of the Drell-Yan ratios at small target parton momentum fraction is well described by an existing fit to the shadowing observed in deep-inelastic scattering. The cross section ratios as a function of the incident parton momentum fraction set tight limits on the energy loss of quarks passing through a cold nucleus.

13 data tables

Ratios of measured cross sections per nucleon for Drell Yan events versus di-muon mass.

Ratios of measured cross sections per nucleon for Drell Yan events versus X2.

Ratios of measured cross sections per nucleon for Drell Yan events versus XL.

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Observation of polarization in bottomonium production at s**(1/2) = 38.8-GeV

The NuSea collaboration Brown, C.N. ; Awes, T.C. ; Beddo, M.E. ; et al.
Phys.Rev.Lett. 86 (2001) 2529-2532, 2001.
Inspire Record 536629 DOI 10.17182/hepdata.19423

We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at sqrt(s)=38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state show no polarization at small xF and pT but significant positive transverse production polarization for either pT > 1.8 GeV/c or for xF > 0.35. The Upsilon(2S+3S) unresolved states show a large transverse production polarization at all values of xF and pT measured. These observations are compared with an NRQCD calculation that predicts a transverse polarization in bottomonium production arising from quark-antiquark fusion and gluon-gluon fusion diagrams.

6 data tables

The observed polarization in the Drell-Yan sideband region as a function of PT. There is an additional systematic uncertainty of 0.02 in the polarization measurements.

The observed polarization in the Drell-Yan sideband region as a function of XL. There is an additional systematic uncertainty of 0.02 in the polarization measurements.

The observed polarization in the UPSILON(1S) region as a function of PT. There is an additional systematic error of 0.06 in the polarization measurements.

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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.

1 data table

Upper limit at the 2sigma statistical error level. Mass of MU+ MU- in GeV.


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’.

13 data tables

Ratio of heavy nucleus to deuterium yields. A is the mass number of the target nucleus.

Ratio of heavy nucleus to deuterium yeilds. A is the mass number of the target nucleus.

Ratio of heavy nucleus to deuterium yeilds. A is the mass number of the target nucleus.

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Dimuon production in proton - copper collisions at s**(1/2) = 38.8-GeV

Moreno, G. ; Brown, C.N. ; Cooper, W.E. ; et al.
Phys.Rev.D 43 (1991) 2815-2836, 1991.
Inspire Record 302822 DOI 10.17182/hepdata.22831

Experimental results on the production of dimuons by 800-GeV protons incident on a copper target are presented. The results include measurements of both the continuum of dimuons and the dimuon decays of the three lowest-mass ϒ S states. A description of the apparatus, data acquisition, and analysis techniques is included. A comparison of the results with data taken at lower incident energies indicates a scaling behavior of the continuum dimuon yields.

26 data tables

No description provided.

No description provided.

No description provided.

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Dimuon Production in 800 GeV Proton Nucleus Collisions

Brown, C.N. ; Cooper, W.E. ; Finley, D. ; et al.
Phys.Rev.Lett. 63 (1989) 2637-2640, 1989.
Inspire Record 288346 DOI 10.17182/hepdata.20031

A measurement of continuum dimuon production in proton-copper collisions at 800-GeV incident energy is presented. The dimuons observed in this experiment cover the mass range from 6.5 to 18 GeV near y=0 in the proton-nucleon center-of-momentum frame. Scaling forms of the cross section for the continuum are compared with the results of other experiments in the context of the parton model and quantum chromodynamics. The present limitations of such scaling comparisons are discussed.

1 data table

No description provided.


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.

10 data tables

High Mass trigger data.

Intermediate Mass trigger data.

Low Mass trigger data.

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