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rivet Analysis
A study of the energy evolution of event shape distributions and their means with the DELPHI detector at LEP.

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Eur.Phys.J.C 29 (2003) 285-312, 2003.
Inspire Record 620250 DOI 10.17182/hepdata.13029

Infrared and collinear safe event shape distributions and their mean values are determined in e+e- collisions at centre-of-mass energies between 45 and 202 GeV. A phenomenological analysis based on power correction models including hadron mass effects for both differential distributions and mean values is presented. Using power corrections, alpha_s is extracted from the mean values and shapes. In an alternative approach, renormalisation group invariance (RGI) is used as an explicit constraint, leading to a consistent description of mean values without the need for sizeable power corrections. The QCD beta-function is precisely measured using this approach. From the DELPHI data on Thrust, including data from low energy experiments, one finds beta_0 = 7.86 +/- 0.32 for the one loop coefficient of the beta-function or, assuming QCD, n_f = 4.75 +/- 0.44 for the number of active flavours. These values agree well with the QCD expectation of beta_0=7.67 and n_f=5. A direct measurement of the full logarithmic energy slope excludes light gluinos with a mass below 5 GeV.

71 data tables
Table 1

1-THRUST distribution.

Table 2

THRUST-MAJOR distribution.

Table 3

THRUST-MINOR distribution.

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Charge Asymmetry of Hadron Jets and Limits on the Compositeness Scales in e$^{+} $e$^{-} \To $q$ \Bar{$q$}$ Reaction at $\Sqrt{$s$}=57$.6-{GeV}

The VENUS collaboration Abe, K. ; Amako, K. ; Arai, Y. ; et al.
Phys.Lett.B 232 (1989) 425-430, 1989.
Inspire Record 281245 DOI 10.17182/hepdata.29751

A charge asymmetry has been measured in hadron jets from e + e − annihilation at energies between 52 and 61.4 geV (〈√ s 〉=57.6 GeV). The measured asymmetry is A =11.4%±2.2%±2.1% and is consistent with the prediction of the standard model of the electroweak theory. By using the differential cross section, lower limits of the compositeness scale in eeqq contact interactions have been determined to be typically a few TeV at 95% CL.

1 data table
Table 1

Data are fully corrected for detector effects, resolution and radiative effects.


Determination of the QCD scale parameter Lambda (ms) with QCD cascade on the basis of the next-to-leading logarithmic approximation

The VENUS collaboration Abe, K. ; Amako, K. ; Arai, Y. ; et al.
Phys.Lett.B 240 (1990) 232-236, 1990.
Inspire Record 296684 DOI 10.17182/hepdata.29690

The relative production ratio of 3-jet events to the total number of hadronic events was studied in e + e − annihilations at centre-of-mass energies between 54 and 61.4 GeV. The QCD scale parameter has been determined to be Λ MS =254 −47 +55 ±56 MeV on the basis of a QCD cascade with the next-to-leading logarithmic approximation.

2 data tables
Table 1

Data are uncorrected for initial radiation, detector effects, and quark hadronization.

Table 2

LAMBDA-MSBAR determined from the 3-jet ratio.