Precision NNLO determination of alpha(s)(M-Z) using an unbiased global parton set

TY - JOUR

T1 - Precision NNLO determination of alpha(s)(M-Z) using an unbiased global parton set

AU - Ball, R.D.

AU - Del Debbio, L.

AU - Bertone, V.

AU - Forte, S.

AU - Guffanti, Alberto

AU - Latorre, J.I.

AU - Lionetti, S.

AU - Rojo, J.

AU - Ubiali, M.

PY - 2012/1/16

Y1 - 2012/1/16

N2 - We determine the strong coupling α s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inelastic scattering, Drell-Yan, vector boson production and inclusive jets. We find α s(M Z)=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 α 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 deep-inelastic data only are used, the best-fit value of α 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 α s is δαspert=0.0018, and we estimate the uncertainty from higher-order corrections to be δαsNNLO~0.0009.

AB - We determine the strong coupling α s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inelastic scattering, Drell-Yan, vector boson production and inclusive jets. We find α s(M Z)=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 α 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 deep-inelastic data only are used, the best-fit value of α 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 α s is δαspert=0.0018, and we estimate the uncertainty from higher-order corrections to be δαsNNLO~0.0009.

U2 - 10.1016/j.physletb.2011.11.053

DO - 10.1016/j.physletb.2011.11.053

M3 - Journal article

SN - 0370-2693

VL - 707

SP - 66

EP - 71

JO - Physics Letters B: Particle Physics, Nuclear Physics and Cosmology

JF - Physics Letters B: Particle Physics, Nuclear Physics and Cosmology

IS - 1

ER -