HEPData Search

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Properties of hadronic Z decays and test of QCD generators

The ALEPH collaboration Buskulic, D. ; Decamp, D. ; Goy, C. ; et al.

Z.Phys.C 55 (1992) 209-234, 1992.

Inspire Record 334577 DOI 10.17182/hepdata.1420

Distributions are presented of event shape variables, jet roduction rates and charged particle momenta obtained from 53 000 hadronicZ decays. They are compared to the predictions of the QCD+hadronization models JETSET, ARIADNE and HERWIG, and are used to optimize several model parameters. The JETSET and ARIADNE coherent parton shower (PS) models with running αs and string fragmentation yield the best description of the data. The HERWIG parton shower model with cluster fragmentation fits the data less well. The data are in better agreement with JETSET PS than with JETSETO(αS2) matrix elements (ME) even when the renormalization scale is optimized.

41 data tables

Table 1

Sphericity distribution.

Table 2

Sphericity distribution.

Table 3

Aplanarity distribution.

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Forward produced hadrons in mu p and mu d scattering and investigation of the charge structure of the nucleon

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, G. ; et al.

Z.Phys.C 52 (1991) 361-388, 1991.

Inspire Record 314883 DOI 10.17182/hepdata.1432

Final data measured with the EMC forward spectrometer are presented on the production of forward charged hadrons in μp and μd scattering at incident beam energies between 100 and 280 GeV. The large statistic of 373 000 events allows a study of the semi-inclusive hadron production as a function ofz,pT2 and 〈pT2〉 in smallQ2,xBj andW bins. Charge multiplicity ratios and differences as a function ofz andxBj are given forp, d andn-targets. From the differences of charge multiplicities the ratio of the valence quark distributions of the protondv(x)/uv(x) is determined for the first time in charged lepton scattering. The Gronau et al. sum rule is tested, the measured sum being 0.31±0.06 stat. ±0.05 syst., compared with the theoretical expectation of 2/7≈0.286. The measured sum corresponds to an absolute value of the ratio of thed andu quark charge of 0.44±0.10 stat.±0.08 syst.

129 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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General characteristics of pi- mesons produced in d (C), alpha (C) interactions at 1-GeV/N and 3.3-GeV/N

Viryasov, N.M. ; Gulkanian, G.R. ; Kakoyan, V.G. ; et al.

JINR-P1-90-521, 1990.

Inspire Record 304495 DOI 10.17182/hepdata.38730

None

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Cumulative production of pi- mesons in pi C interactions at 40-GeV/c

Baatar, Ts. ; Batsaikhan, Ts. ; Ivanovskaya, I.A. ; et al.

Sov.J.Nucl.Phys. 52 (1990) 504-508, 1990.

Inspire Record 299082 DOI 10.17182/hepdata.38727

None

7 data tables

Table 1

HERE XL IS CUMULATIVE NUMBER, DEFINED AS FOLLOWS: (E-PL)/M(NUCLEON). THE DISTRIBUTION (1/N)*D(N)/D(XL) WAS FITTED BY THE SUM: CONST(1)* EXP(-SLOPE(1)*XL)+CONST(2)*EXP(-SLOPE(2)*XL).

Table 2

HERE XL IS CUMULATIVE NUMBER, DEFINED AS FOLLOWS: (E-PL)/M(NUCLEON). THE DISTRIBUTION (XL/N)*D(N)/D(XL) WAS FITTED BY THE SUM: CONST(1)* EXP(-SLOPE(1)*XL)+CONST(2)*EXP(-SLOPE(2)*XL).

Table 3

HERE XL IS CUMULATIVE NUMBER, DEFINED AS FOLLOWS: (E-PL)/M(NUCLEON).

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Study of Hadronic Decays of the $\Z^0$ Boson

The DELPHI collaboration Aarnio, P. ; Abreu, P. ; Adam, W. ; et al.

Phys.Lett.B 240 (1990) 271-282, 1990.

Inspire Record 294894 DOI 10.17182/hepdata.49562

Hadronic decays of Z 0 bosons are studied in the Delphi detector. Global event variables and singel particles inclusive distributions are compared with QCD-based predictions. The mean charged multiplicity is found to be 20.6±1.0 (stat+syst). The mean values of the sphericity, aplanarity, thrust, minor value, p in T and p out T are compared with values found at lower energy e + e − colliders.

13 data tables

Table 1

Corrected Sphericity distribution. Statistical errors only.

Table 2

Corrected Aplanarity distribution. Statistical errors only.

Table 3

Corrected Q3-Q2 distribution. Statistical errors only.

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Inclusive spectra of pi- mesons with cumulative number n(c) > 0.35 produced in d C, He C, and C C interactions at 4.2-GeV/c per nucleon.

Baatar, Ts. ; Batsaikhan, Ts. ; Ivanovskaya, I.A. ; et al.

Sov.J.Nucl.Phys. 53 (1991) 292-296, 1991.

Inspire Record 295859 DOI 10.17182/hepdata.38726

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

MOMENTUM AND ANGULAR DISTRIBUTIONS OF pi- MESONS PRODUCED IN d C INTERACTIONS AT 1-GeV/N

Viryasov, N.M. ; Grigorian, V.A. ; Gulkanian, G.R. ; et al.

JINR-P1-89-511, 1989.

Inspire Record 285509 DOI 10.17182/hepdata.38758

None

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

(1/N)*D(N)/D(P) HAS BEEN FITTED BY (P/MEAN(N=P))**POWER* EXP(-SLOPE*SQRT(P/MEAN(N=P))).

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Central Collisions of 800-{GeV} Protons With Ag / Br Nuclei in Nuclear Emulsion

The BATON ROUGE-KRAKOW-MOSCOW-TASHKENT collaboration Abduzhamilov, A. ; Barbier, L.M. ; Chernova, L.P. ; et al.

Phys.Rev.D 39 (1989) 86-91, 1989.

Inspire Record 280844 DOI 10.17182/hepdata.3813

Central collisions of 800-GeV protons with the heavy components of nuclear emulsion, Ag107 and Br80, have been investigated to determine the characteristics of small-impact-parameter collisions and, by comparison with the analysis of inclusive proton-emulsion inelastic interactions and inelastic proton-nucleon collisions, to study the dependence of the interaction process on the mean number of intranuclear collisions 〈ν〉. The data are also compared with the results obtained in proton-emulsion collisions, both central and inclusive, at 200 GeV. The variations in the secondary-particle multiplicities and the normalized pseudorapidity density correlate with 〈ν〉 and demonstrate that proton-nucleus interactions, both central and inclusive, can be described adequately by the incoherent superposition of proton-nucleon collisions.

5 data tables

Table 1

NUCLEUS IS AVERAGE NUCLEUS OF EMULSION.

Table 2

NUCLEUS IS AVERAGE NUCLEUS OF EMULSION.

Table 3

NUCLEUS IS AVERAGE NUCLEUS OF EMULSION.

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Measurements of the $u$ Valence Quark Distribution Function in the Proton and $u$ Quark Fragmentation Functions

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.

Nucl.Phys.B 321 (1989) 541-560, 1989.

Inspire Record 276746 DOI 10.17182/hepdata.33218

A new determination of the u valence quark distribution function in the proton is obtained from the analysis of identified charged pions, kaons, protons and antiprotons produced in muon-proton and muon-deuteron scattering. The comparison with results obtained in inclusive deep inelastic lepton-nucleon scattering provides a further test of the quark-parton model. The u quark fragmentation functions into positive and negative pions, kaons, protons and antiprotons are also measured.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.