Adams, M.R.
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n p elastic spin transfer measurements at 485-MeV and 635-MeV

McNaughton, K.H. ; Ambrose, D.A. ; Coffey, P. ; et al.
Phys.Rev.C 46 (1992) 47-51, 1992.
Inspire Record 342389 DOI 10.17182/hepdata.26097

We have measured the spin-transfer parameters KLL, KSL, KLS, and KSS at 635 MeV from 50° to 178° c.m. and at 485 MeV from 74° to 176° c.m. These new data have a significant impact on the phase-shift analyses. There are now sufficient data near these energies to overdetermine the elastic nucleon-nucleon amplitudes.

2 data tables
Table 1

Spin transfer parameters from np elastic scattering at 635 MeV. There is an additional overall normalisation of 2 PCT.

Table 2

Spin transfer parameters from np elastic scattering at 485 MeV. There is an additional overall normalisation of 2 PCT.


Determination of $alpha_{s}$ in second order {QCD} from hadronic $Z$ decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Z.Phys.C 54 (1992) 55-74, 1992.
Inspire Record 333272 DOI 10.17182/hepdata.14603

Distributions of event shape variables obtained from 120600 hadronicZ decays measured with the DELPHI detector are compared to the predictions of QCD based event generators. Values of the strong coupling constant αs are derived as a function of the renormalization scale from a quantitative analysis of eight hadronic distributions. The final result, αs(MZ), is based on second order perturbation theory and uses two hadronization corrections, one computed with a parton shower model and the other with a QCD matrix element model.

9 data tables
Table 1

Experimental differential Thrust distributions.

Table 2

Experimental differential Oblateness distributions.

Table 3

Experimental differential C-parameter distributions.

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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
Table 1

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


Nuclear dependence of high x(t) hadron and high tau hadron pair production in p A interactions at s**(1/2) = 38.8-GeV

Straub, P.B. ; Jaffe, D.E. ; Glass, Henry D. ; et al.
Phys.Rev.Lett. 68 (1992) 452-455, 1992.
Inspire Record 335754 DOI 10.17182/hepdata.19847

We present a high-statistics, species-identified measurement of the W-to-Be per-nucleon cross-section ratio, RW/Be, for high-xt hadrons and high-τ h+h− pairs produced in p-A collisions at √s =38.8 GeV. The data extend to 0.62 in xt and 0.39 in √τ . For single hadrons, RW/Be peaks at pt≊5 GeV/c and decreases to ≊1 for mesons with pt>8 GeV/c. At fixed pt, RW/Be falls with √s . For symmetric pairs with √τ >0.28, RW/Be=0.84±0.02±0.07, suggesting a nuclear suppression of high-z fragmentation. RW/Be increases with pout, indicative of constituent multiple scattering.

1 data table
Table 1

No description provided.


Shadowing in the muon-xenon inelastic scattering cross-section at 490-GeV

The Fermilab E665 collaboration Adams, M.R. ; Aid, S. ; Anthony, P.L. ; et al.
Phys.Lett.B 287 (1992) 375-380, 1992.
Inspire Record 341389 DOI 10.17182/hepdata.29153

Inelastic scattering of 490 GeV μ + from deuterium and xenon nuclei has been studied for x Bj > s .001. The ratio of the xenon/deuterium cross section per nucleon is observed to vary with x Bj , with a depletion in the kinematic range 0.001 < x Bj < 0.025 which exhibits no significant Q 2 dependence. An electromagnetic calorimeter was used to verify the radiative corrections.

2 data tables
Table 1

Xenon structure function parameterized as being equal to the DEUT structurefunction.

Table 2

Xenon structure function parameterized by an x-dependent shadowing factor times the DEUT structure function.


Saturation of shadowing at very low x(Bj)

The E665 collaboration Adams, M.R. ; Aid, S. ; Anthony, P.L. ; et al.
Phys.Rev.Lett. 68 (1992) 3266-3269, 1992.
Inspire Record 333894 DOI 10.17182/hepdata.19864

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.

2 data tables
Table 1

Data using Electromagnetic Cuts.

Table 2

Data using Hadron Requirement.


rivet Analysis
Charged particle multiplicity distributions for fixed number of jets in Z0 hadronic decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Z.Phys.C 56 (1992) 63-76, 1992.
Inspire Record 334948 DOI 10.17182/hepdata.14533

The multiplicity distributions of charged particles in full phase space and in restricted rapidity intervals for events with a fixed number of jets measured by the DELPHI detector are presented. The data are well reproduced by the Lund Parton Shower model and can also be well described by fitted negative binomial distributions. The properties of these distributions in terms of the clan model are discussed. In symmetric 3-jet events the candidate gluon jet is found not to be significantly different in average multiplicity than the mean of the other two jets, thus supporting previous results of the HRS and OPAL experiments. Similar results hold for events generated according to the LUND PS and to the HERWIG models, when the jets are defined by the JADE jet finding algorithm. The method seems to be insensitive for measuring the color charge ratio between gluons and quarks.

3 data tables
Table 1

Corrected charged particle multiplicity for jet resolution parameter YCUT = 0.01.

Table 2

Corrected charged particle multiplicity for jet resolution parameter YCUT = 0.02.

Table 3

Corrected charged particle multiplicity for jet resolution parameter YCUT = 0.04.


Measurement of inclusive production of light meson resonances in hadronic decays of the Z0

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 298 (1993) 236-246, 1993.
Inspire Record 342800 DOI 10.17182/hepdata.29001

A study of inclusive production of the meson resonances ρ 0 , K ∗0 (892), ƒ 0 (975) and ƒ 2 (1270) in hadronic decays of the Z 0 is presented. The measured mean meson multiplicity per hadronic event is 0.83 ± 0.14 for the ρ 0 0.64 ± 0.24 for the K ∗0 (892), 0.10 ± 0.04 for the ƒ 0 (975) in the momentum range p > 0.05 p beam ( x p > 0.05) and 0.11 ± 0.05 for the ƒ 2 (1270) for x p > 0.1 . These values and the corresponding differential cross sections ( 1 σ hadr ) d σ d x p for the vector mesons are in good agreement with the predictions of the JETSET 7.3 PS and HERWIG 5.4 models. The ƒ 2 (1270) production is overestimated by HERWIG but its x p -shape is correctly reproduced. The measured ratios of the production cross sections σ(ƒ 2 (1270)) σ(ρ 0 ) = 0.22 ± 0.08 and σ(ƒ 2 (1270)) σ(ƒ 0 (975)) = 3 −1 +7 for x p > 0.1 are consistent with the results obtained in hadronic reactions.

10 data tables
Table 1

Average multiplicity per hadronic event. Extrapolation to x = 0 using the x shape predicted by JETSET 7.3 PS.

Table 2

Average multiplicity per hadronic event. Extrapolation to x = 0 using the x shape predicted by JETSET 7.3 PS.

Table 3

Average multiplicity per hadronic event. Extrapolation to x = 0 using the x shape predicted by JETSET 7.3 PS.

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Absolute p p elastic cross-sections from 492-MeV to 793-MeV

Simon, A.J. ; Glass, G. ; McNaughton, M.W. ; et al.
Phys.Rev.C 48 (1993) 662-675, 1993.
Inspire Record 363783 DOI 10.17182/hepdata.26001

Absolute pp-elastic-differential cross sections were measured at incident energies 492, 576, 642, 728, and 793 MeV from about 30° to 90° c.m. The total uncertainty was determined to be less than 1%, made possible by particle counting for beam normalization and extensive cross-checks of systematic effects. These new data are consistent with previous data above 600 MeV but have uncertainties about a factor of 10 smaller. Near 500 MeV these data are consistent with 90° data from TRIUMF, but differ significantly from similar data from PSI; the cause of this discrepancy is discussed.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurement of the ratio sigma(n) / sigma(p) in inelastic muon - nucleon scattering at very low x and Q**2

The E665 collaboration Adams, M.R. ; Aïd, S. ; Anthony, P.L. ; et al.
Phys.Lett.B 309 (1993) 477-482, 1993.
Inspire Record 354238 DOI 10.17182/hepdata.28907

We present results on the cross-section ratio for inelastic muon scattering on neutrons and protons as a function of Bjorken chi;. The data extend to χ values two orders of magnitude smaller than in previous measurements, down to 2×10 −5 , for Q 2 >0.01 GeV 2 . The ratio is consistent with unity throughout this new range.

2 data tables
Table 1

No description provided.

Table 2

No description provided.