Journal Article

Determination of αS using OPAL hadronic event shapes at and resummed NNLO calculations

Yamashita, S., Geich-Gimbel, C., Orito, S., Quadt, A., Pahl, C., Frey, A., Chang, C. Y., Anderson, K. J., Dallavalle, M., Giunta, M., Barlow, R. J., Barillari, T., Bailey, I., Desch, K., Turner-Watson, M. F., Ciocca, C., Braibant, S., Kawamoto, T., Csilling, A., Vossebeld, J., Seuster, R., Pater, J. R., Giacomelli, G., Kennedy, B. W., Capiluppi, P., Carter, J. R., Hawkes, C. M., Schaile, O., Trócsányi, Z., Nakamura, I., Ludwig, J., Schumacher, M., Kawagoe, K., Meijers, F., Junk, T. R., Vollmer, C. F., Michelini, A., Smith, A. M., Wyatt, T. R., Bethke, S., Sachs, K., Plane, D. E., Wilson, J. A., Hawkings, R., Anagnostou, G., Karlen, D., Saeki, T., Abbiendi, G., O’Neale, S. W., Thomson, M. A., Watkins, P. M., Kuhl, T., Loebinger, F. K., Teuscher, R., Mättig, P., Mashimo, T., Tasevsky, M., Mikenberg, G., Letts, J., Duchovni, E., Axen, D., Hajdu, C., Ishii, K., Ueda, I., Boutemeur, M., Torrence, E., Gross, E., Mutter, A., Vannerem, P., Tarem, S., Jeremie, H., Cuffiani, M., Kanzaki, J., Meyer, N., Jovanovic, P., Menges, W., Ujvári, B., Fiedler, F., Verzocchi, M., Carnegie, R. K., Dienes, B., Biebel, O., Barberio, E., Kobel, M., Ford, M., Levinson, L., Ströhme

2011

Overview

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 α 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 resummed next-to-leading-log-approximation terms (NNLO + NLLA). The combined NNLO result from all variables and centre-of-mass energies is while the combined NNLO + NLLA result is 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 α S agrees with the QCD prediction of asymptotic freedom and excludes the absence of running.

• Publisher: Springer-Verlag,Springer Nature B.V
• Subject: Astronomy / Astrophysics and Cosmology / Dependence / Elementary Particles / Hadrons / Heavy Ions / Mathematical analysis / Measurement Science and Instrumentation / Nuclear Energy / Nuclear Physics / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Regular Article - Experimental Physics / String Theory