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arXiv · hep-ph/9803254

Determination of Lambda_QCD from the measured energy dependence of <1-Thrust>

J. M. Campbell·E. W. N. Glover·C. J. Maxwell
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Abstract

We directly fit the experimentally measured energy dependence of the average value of 1-Thrust, <1-T>, over the e^+e^- centre-of-mass energy range Q=14 - 172 GeV to the QCD expectation obtained by integrating up the evolution equation for d<1-T>/dlog Q in terms of <1-T>. We fit for Lambda_QCD, uncalculated O(alpha_S^3) and higher perturbative corrections parameterized by the scheme invariant rho_2, and the parameter lambda which characterizes the magnitude of the leading 1/Q power corrections anticipated for <1-T>. A 3-parameter fit yields Lambda_QCD=245^{+20}_{-17} MeV, rho_2=-16\pm 11 and lambda=0.27^{+0.12}_{-0.10} GeV, equivalent to alpha_S(M_Z)=0.1194 \pm 0.0014. In this approach, there is no error associated with the choice of the renormalization scale mu.

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J. M. Campbell, E. W. N. Glover, C. J. Maxwell. 1998-05-27. Determination of Lambda_QCD from the measured energy dependence of <1-Thrust>. https://doi.org/10.1103/physrevlett.81.1568

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