LAMQCD
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Energy-energy correlations in hadronic final states from Z0 decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Phys.Lett.B 252 (1990) 149-158, 1990.
Inspire Record 300161 DOI 10.17182/hepdata.29534

We have studied the energy-energy angular correlations in hadronic final states from Z 0 decay using the DELPHI detector at LEP. From a comparison with Monte Carlo calculations based on the exact second order QCD matrix element and string fragmentation we find that Λ (5) MS =104 +25 -20 ( stat. ) +25 -20( syst. ) +30 00 ) theor. ) . MeV, which corresponds to α s (91 GeV)=0.106±0.003(stat.)±0.003(syst.) +0.003 -0.000 (theor). The theoretical error stems from different choices for the renormalization scale of α s . In the Monte Carlo simulation the scale of α s as well as the fragmentation parameters have been optimized to described reasonably well all aspects of multihadron production.

2 data tables
Table 1

Data requested from the authors.

Table 2

Values of LAMBDA-MSBAR(5) and ALPHA-S(91 GeV) deduced from the EEC measurements. The second systematic error is from the theory.


Determination of $\alpha^- s$ From a Differential Jet Multiplicity Distribution at {SLC} and {PEP}

Komamiya, Sachio ; Le Diberder, F. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 64 (1990) 987, 1990.
Inspire Record 283630 DOI 10.17182/hepdata.19937

We measured the differential jet-multiplicity distribution in e+e− annihilation with the Mark II detector. This distribution is compared with the second-order QCD prediction and αs is determined to be 0.123±0.009±0.005 at √s≊MZ (at the SLAC Linear Collider) and 0.149±0.002±0.007 at √s=29 GeV (at the SLAC storage ring PEP). The running of αs between these two center-of-mass energies is consistent with the QCD prediction.

2 data tables
Table 1

DIFFERENTIAL JET MULTIPLICITIES.

Table 2

DIFFERENTIAL JET MULTIPLICITIES.