Date

Angular distribution of the production of symmetric hadron pairs in pi- p collisions at 40-GeV

Volkov, A.A. ; Kostritsky, A.V. ; Abramov, V.V. ; et al.
JETP Lett. 58 (1993) 486-492, 1993.
Inspire Record 346766 DOI 10.17182/hepdata.40644

None

7 data tables

No description provided.

No description provided.

No description provided.

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Narrow baryonia with open and hidden strangeness.

The EXCHARM collaboration Aleev, A.N. ; Balandin, V.P. ; Chvyrov, A.S. ; et al.
Phys.Atom.Nucl. 56 (1993) 1358-1366, 1993.
Inspire Record 344917 DOI 10.17182/hepdata.17233

None

4 data tables

NUCLEUS IS P, C, AL, CU.

NUCLEUS IS P, C, AL, CU.

NUCLEUS IS P, C, AL, CU.

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A Global determination of alpha-s (M(z0)) at LEP

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 55 (1992) 1-24, 1992.
Inspire Record 333079 DOI 10.17182/hepdata.14606

The value of the strong coupling constant,$$\alpha _s (M_{Z^0 } )$$, is determined from a study of 15 d

16 data tables

Differential jet mass distribution for the heavier jet using method T. The data are corrected for the finite acceptance and resolution of the detector and for initial state photon radiation.

Differential jet mass distribution for the jet mass difference using methodT. The data are corrected for the finite acceptance and resolution of the detec tor and for initial state photon radiation.

Differential jet mass distribution for the heavier jet using method M. The data are corrected for the finite acceptance and resolution of the detector and for initial state photon radiation.

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Measurement of alpha-s in hadronic Z decays using all orders resummed predictions

The ALEPH collaboration Decamp, D. ; Deschizeaux, B. ; Goy, C. ; et al.
Phys.Lett.B 284 (1992) 163-176, 1992.
Inspire Record 333334 DOI 10.17182/hepdata.48421

None

1 data table

Three different methods are used for extraction Alphas value (see text for details). Systematical errors with C=HADR and C=THEOR are due to hadronization correction and theoretical uncertainties.


Evidence for the triple gluon vertex from measurements of the QCD color factors in Z decay into four jets

The ALEPH collaboration Decamp, D. ; Deschizeaux, B. ; Goy, C. ; et al.
Phys.Lett.B 284 (1992) 151-162, 1992.
Inspire Record 333127 DOI 10.17182/hepdata.48505

None

1 data table

NC, CF, and TF are the color factors for SU(N) group. For SU(3) they are equal to: NC = 3, CF = 4/3, and TF = 1/2.


Evidence for b flavored baryon production in Z0 decays at LEP

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, J. ; et al.
Phys.Lett.B 281 (1992) 394-404, 1992.
Inspire Record 333300 DOI 10.17182/hepdata.48511

We observe evidence for the production of b-flavoured baryons in decays of the Z 0 boson with the OPAL detector at LEP. We find 68 Λl − , Λ l + candidates in 458 583 hadronic Z 0 decays. We interpret this as a signal of 55 ± 9 +0.3 −3.1 events from the semi-leptonic decays of b baryons. Assuming weakly decaying b baryons produced in Z 0 decays are mostly Λ b particles, we measure the product branching ratio (Γ b b /Γ had ) f ( b →Λ b ) B (Λ b →Λl − v X ) , averaged over the electron and muon channels, to be (6.2±1.0±1.5)×10 −4 .

1 data table

FD is considered as a quark fragmentation fraction. Charge conjugated state is understood.


Studies of hadronic event structure and comparisons with QCD models at the Z0 resonance

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Z.Phys.C 55 (1992) 39-62, 1992.
Inspire Record 334954 DOI 10.17182/hepdata.14566

The structure of hadronic events fromZ0 decay is studied by measuring event shape variables, factorial moments, and the energy flow distribution. The distributions, after correction for detector effects and initial and final state radiation, are compared with the predictions of different QCD Monte Carlo programs with optimized parameter values. These Monte Carlo programs use either the second order matrix element or the parton shower evolution for the perturbative QCD calculations and use the string, the cluster, or the independent fragmentation model for hadronization. Both parton shower andO(α2s matrix element based models with string fragmentation describe the data well. The predictions of the model based on parton shower and cluster fragmentation are also in good agreement with the data. The model with independent fragmentation gives a poor description of the energy flow distribution. The predicted energy evolutions for the mean values of thrust, sphericity, aplanarity, and charge multiplicity are compared with the data measured at different center-of-mass energies. The parton shower based models with string or cluster fragmentation are found to describe the energy dependences well while the model based on theO(α2s calculation fails to reproduce the energy dependences of these mean values.

16 data tables

Unfolded Thrust distribution. Statistical error includes statistical uncertainties of the data as well as of the unfolding Monte Carlo Sample. The systematic error combines the uncertainties of measurements and of the unfolding procedure.

Unfolded Major distribution where Major is defined in the same way as Thrust but is maximized in a plane perpendicular to the Thrust axis.

Unfolded Minor distribution where the minor axis is defined to give an orthonormal system.

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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

2 data tables

Data using Electromagnetic Cuts.

Data using Hadron Requirement.


Study of the reaction pi- p ---> eta-prime eta-prime n

Berdnikov, E.B. ; Bityukov, S.I. ; Borisov, G.V. ; et al.
Z.Phys.C 57 (1993) 13-16, 1993.
Inspire Record 340793 DOI 10.17182/hepdata.14498

The reaction π−p→η′η′n has been studied atpπ=37 GeV/c. Total of 14 events of this reaction have been selected. It has been shown that in the effective mass spectrum of the η′η′ system the events are concentrated mainly near the reaction threshold, which might be caused by the decayX(1910)→η′η′. The reaction cross-section has been evaluated: σ(π−p→η′η′n)=110±40 nb.

2 data tables

No description provided.

No description provided.


Determination of alpha-s from hadronic event shapes measured on the Z0 resonance

The L3 collaboration Adrian, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.
Phys.Lett.B 284 (1992) 471-481, 1992.
Inspire Record 334951 DOI 10.17182/hepdata.29157

We present a study of the global event shape variables thrust and heavy jet mass, of energy-energy correlations and of jet multiplicities based on 250 000 hadronic Z 0 decays. The data are compared to new QCD calculations including resummation of leading and next-to-leading logarithms to all orders. We determine the strong coupling constant α s (91.2 GeV) = 0.125±0.003 (exp) ± 0.008 (theor). The first error is the experimental uncertainty. The second error is due to hadronization uncertainties and approximations in the calculations of the higher order corrections.

3 data tables

Measured EEC distribution corrected for detector effects and photon radiation. Errors are combined statistical and systematic uncertainties.

Measured average jet multiplicities for the K_PT algorithm. All numbers are corrected for detector effects and photon radiation. Errors are combined statistical and systematic uncertainties.

Value of strong coupling constant, alpha_s, determined from the data. First error is experimental, the second is theoretical.