https://doi.org/10.1140/epjc/s10052-018-5897-7
Regular Article - Theoretical Physics
Precision determination of the strong coupling constant within a global PDF analysis
NNPDF Collaboration
1
The Higgs Centre for Theoretical Physics, University of Edinburgh, JCMB, KB, Mayfield Rd, Edinburgh, Scotland, EH9 3JZ, UK
2
Theoretical Physics Department, CERN, 1211, Geneva, Switzerland
3
Tif Lab, Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano, Via Celoria 16, 20133, Milan, Italy
4
Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
5
Department of Physics and Astronomy, VU University, 1081 HV, Amsterdam, The Netherlands
6
Nikhef Theory Group, Science Park 105, 1098 XG, Amsterdam, The Netherlands
7
Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford, OX1 3NP, UK
8
DAMTP, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK
* e-mail: stefano.forte@mi.infn.it
Received:
27
March
2018
Accepted:
14
May
2018
Published online:
24
May
2018
We present a determination of the strong coupling constant 
based on the NNPDF3.1 determination of parton distributions, which for the first time includes constraints from jet production, top-quark pair differential distributions, and the Z
distributions using exact NNLO theory. Our result is based on a novel extension of the NNPDF methodology – the correlated replica method – which allows for a simultaneous determination of 
and the PDFs with all correlations between them fully taken into account. We study in detail all relevant sources of experimental, methodological and theoretical uncertainty. At NNLO we find 
, showing that methodological uncertainties are negligible. We conservatively estimate the theoretical uncertainty due to missing higher order QCD corrections (N
LO and beyond) from half the shift between the NLO and NNLO values, finding 
.
© The Author(s), 2018
