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Abstract
We determine the strong coupling alpha(s) at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deepinelastic scattering. DrellYan, vector boson production and inclusive jets. We find alpha(s)(MZ) = 0.1173 +/ 0.0007(stat), where the statistical uncertainty comes from the underlying data and uncertainties due to the analysis procedure are negligible. We show that the distribution of alpha(s) values preferred by different experiments in the global fit is statistically consistent, without need for rescaling uncertainties by a "tolerance" factor. We show that if deepinelastic data only are used, the bestfit value of alpha(s) is somewhat lower, but consistent within one sigma with the global determination. We find that the shift between the NLO and NNLO values of alpha(s) is Delta alpha(pert)(s) = 0.0018, and we estimate the uncertainty from higherorder corrections to be Delta alpha(NNLO)(s) similar to 0.0009. (C) 2011 Elsevier B.V. All rights reserved.
Original language  English 

Pages (fromto)  6671 
Number of pages  6 
Journal  Physics Letters B 
Volume  707 
Issue number  1 
DOIs  
Publication status  Published  16 Jan 2012 
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 1 Finished

Particle Theory at the Tait Institute
Ball, R., Berera, A., Boyle, P., Del Debbio, L., FigueroaO'Farrill, J., Gardi, E., Horsley, R., Kennedy, A., Kenway, R., Pendleton, B. & Simon Soler, J.
1/10/11 → 30/09/15
Project: Research