A Precise Determination of ${\alpha }_s$ from the C-parameter Distribution

Abstract

We present a global fit for ${\alpha }_s(m_Z)$, analyzing the available C-parameter data measured at center-of-mass energies between $Q=35$ and $207$ GeV. The experimental data is compared to a N${}^3$LL${}^{\prime }$ + $\mathcal{O}({\alpha }_s^3)$ + ${\Omega }_1$ theoretical prediction (up to the missing 4-loop cusp anomalous dimension), which includes power corrections coming from a field theoretical nonperturbative soft function. The dominant hadronic parameter is its first moment ${\Omega }_1$, which is defined in a scheme which eliminates the $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ renormalon ambiguity. The resummation region plays a dominant role in the C-parameter spectrum, and in this region a fit for ${\alpha }_s(m_Z)$ and ${\Omega }_1$ is sufficient. We find ${\alpha }_s(m_Z)=0.1123\pm 0.0015$ and ${\Omega }_1=0.421\pm 0.063\mathrm{GeV}$ with ${\chi }^2/\mathrm{dof}=0.988$ for $404$ bins of data. These results agree with the prediction of universality for ${\Omega }_1$ between thrust and C-parameter within 1-$\sigma$.

24 pages, 19 figures

References in corpus (19)

• Thrust at N^3LL with Power Corrections and a Precision Global Fit for alphas(mZ)
• Quark and gluon form factors to three loops
• A precise determination of alpha_s from LEP thrust data using effective field theory
• Treating the b quark distribution function with reliable uncertainties
• NNLO corrections to event shapes in $e^{+}{e}^{-}$ annihilation
• NNLO corrections to 3-jet observables in electron-positron annihilation
• Momentum Flow Correlations from Event Shapes: Factorized Soft Gluons and Soft-Collinear Effective Theory
• Toward a NNLO calculation of the B-->X_s+gamma decay rate with a cut on photon energy: II. Two-loop result for the jet function
• Second-order QCD corrections to the thrust distribution
• High-precision quark masses and QCD coupling from $n_f=4$ lattice QCD
• Resummation of heavy jet mass and comparison to LEP data
• Event shapes and jet rates in electron-positron annihilation at NNLO
• Designing Gapped Soft Functions for Jet Production
• The strong coupling from the revised ALEPH data for hadronic $\tau$ decays
• First determination of the strong coupling constant using NNLO predictions for hadronic event shapes in e^+e^- annihilations
• Determination of the strong coupling constant using matched NNLO+NLLA predictions for hadronic event shapes in e+e- annihilations
• NNLO moments of event shapes in e+e- annihilation
• Non-Perturbative Contribution to the Thrust Distribution in $e^{+}{e}^{-}$ Annihilation
• Renormalization of Subleading Dijet Operators in Soft-Collinear Effective Theory

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• Towards parton distribution functions with small-$x$ resummation: HELL 2.0
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• Determination of the strong coupling constant ${\alpha }_s(m_Z)$ from measurements of the total cross section for top-antitop quark production
• Removing phase-space restrictions in factorized cross sections