Study of prompt photon production in hadronic Z0 decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 69 (1995) 1-14, 1995.
Inspire Record 397391 DOI 10.17182/hepdata.48136

None

3 data tables

Rates for gamma + 1 jet.

Rates for gamma + 2 jet.

Rates for gamma + 3 jet.


Determination of alpha-s using the next-to-leading log approximation of QCD

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 59 (1993) 21-34, 1993.
Inspire Record 354909 DOI 10.17182/hepdata.50115

A new measurement of αs is obtained from the distributions in thrust, heavy jet mass, energy-energy correlation and two recently introduced jet broadening variables following a method proposed by Cata

7 data tables

Thrust distribution corrected for detector acceptance and initial state photon radiation.

Heavy jet mass (RHO) distribution (THRUST definition) corrected for detect or acceptance and initial state photon radiation.

Heavy jet mass (RHOM) distribution (MASS definition) corrected for detectoracceptance and initial state photon radiation.

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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

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

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

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


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

Experimental differential Thrust distributions.

Experimental differential Oblateness distributions.

Experimental differential C-parameter distributions.

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Experimental study of the triple gluon vertex

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Phys.Lett.B 255 (1991) 466-476, 1991.
Inspire Record 301659 DOI 10.17182/hepdata.48514

In four-jet events from e + e − →Z 0 →multihadrons one can separate the three principal contributions from the triple-gluon vertex, double gluon-bremsstrahlung and the secondary quark-antiquark production, using the shape of the two-dimensional angular distributions in the generalized Nachtmann-Reiter angle θ NR ∗ and the opening angle of the secondary jets. Thus one can identify directly the contribution from the triple-gluon vertex without comparison with a specific non-QCD model. Applying this new method to events taken with the DELPHI-detector we get for the ratio of the colour factor N c to the fermionic Casimir operator C F : N c C F = 2.55 ± 0.55 ( stat. ) ± 0.4 ( fragm. + models ) ± 0.2 ( error in bias ) in agreement with the value 2.25 expected in QCD from N c =3 and C F = 4 3 .

1 data table

NC, CF, and TR are the color factors for SU(3) group.


A Comparison of jet production rates on the Z0 resonance to perturbative QCD

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Phys.Lett.B 247 (1990) 167-176, 1990.
Inspire Record 297698 DOI 10.17182/hepdata.29653

The production rates for 2-, 3-, 4- and 5-jet hadronic final states have been measured with the DELPHI detector at the e + e − storage ring LEP at centre of mass energies around 91.5 GeV. Fully corrected data are compared to O(α 2 s ) QCD matrix element calculations and the QCD scale parameter Λ MS is determined for different parametrizations of the renormalization scale ω 2 . Including all uncertainties our result is α s ( M 2 Z )=0.114±0.003[stat.]±0.004[syst.]±0.012[theor.].

2 data tables

Corrected jet rates.

Second systematic error is theoretical.


Hadron Production by $e^+ e^-$ Annihilation at Center-of-mass Energies Between 2.6-{GeV} and 7.8-{GeV}. Part 2. Jet Structure and Related Inclusive Distributions

Hanson, G. ; Alam, M.S. ; Boyarski, A. ; et al.
Phys.Rev.D 26 (1982) 991, 1982.
Inspire Record 170499 DOI 10.17182/hepdata.38162

We present results on the jet structure observed in multihadronic events produced by e+e− annihilation in the Mark I magnetic detector at SPEAR. The evidence for jet structure and the jet-axis angular distribution are reported. We give inclusive distributions of the hadrons in Feynman x, rapidity, and transverse momentum relative to the jet axis.

19 data tables

Observed particle PT with respect to jet axis for events with three or more detected charged particles.

No description provided.

No description provided.

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