Abbiendi, G. and Ainsley, C. and Akesson, P. F. and Alexander, G. and Anagnostou, G. and Anderson, K. J. and Asai, S. and Axen, D. and Bailey, I. and Barberio, E. and Barillari, T. and Barlow, R. J. and Batley, R. J. and Bechtle, P. and Behnke, T. and Bell, K. W. and Bell, P. J. and Bella, G. and Bellerive, A. and Benelli, G. and Bethke, S. and Biebel, O. and Boeriu, O. and Bock, P. and Boutemeur, M. and Braibant, S. and Brown, R. M. and Burckhart, H. J. and Campana, S. and Capiluppi, P. and Carnegie, R. K. and Carter, A. A. and Carter, J. R. and Chang, C. Y. and Charlton, D. G. and Ciocca, C. and Csilling, A. and Cuffiani, M. and Dado, S. and Dallavalle, M. and De Roeck, A. and De Wolf, E. A. and Desch, K. and Dienes, B. and Dubbert, J. and Duchovni, E. and Duckeck, G. and Duerdoth, I. P. and Etzion, E. and Fabbri, F. (2011) Determination of alpha(S) using OPAL hadronic event shapes at root s=91-209 GeV and resummed NNLO calculations. European Physical Journal C: Particles and Fields, 71 (9): 1733. -. ISSN 1434-6044
Full text not available from this repository.Abstract
Hadronic event shape distributions from e(+)e(-) annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used to determine the strong coupling alpha(S). The results are based on QCD predictions complete to the next-to-next-to-leading order (NNLO), and on NNLO calculations matched to the re-summed next-to-leading-log-approximation terms (NNLO+NLLA). The combined NNLO result from all variables and centre-of-mass energies is alpha(S)(m(Z0)) = 0.1201 +/- 0.0008 (stat.) +/- 0.0013(exp.) +/- 0.0010(had.) +/- 0.0024(theo.) while the combined NNLO + NLLA result is alpha(S)(m(Z0)) = 0.1189 +/- 0.0008(stat.) +/- 0.0016(exp.) +/- 0.0010(had.) +/- 0.0036(theo.) The completeness of the NNLO and NNLO + NLLA results with respect to missing higher order contributions, studied by varying the renormalization scale, is improved compared to previous results based on NLO or NLO + NLLA predictions only. The observed energy dependence of alpha(S) agrees with the QCD prediction of asymptotic freedom and excludes the absence of running.