Related papers: $\alpha_s$ status and perspectives (2018)
We discuss the extraction of alpha_s using isovector hadronic tau decay data and sum rules constructed specifically to suppress contributions associated with poorly known higher dimension condensates. We show, first, that problems with the…
The inclusive jet cross section for proton-proton collisions at a centre-of-mass energy of 7 TeV was measured by the CMS Collaboration at the LHC with data corresponding to an integrated luminosity of 5.0 inverse femtobarns. The measurement…
We extract the value of the strong coupling constant alpha_s from a single-parameter pointlike fit to the photon structure function F_2^gamma at large x and Q^2 and from a first five-parameter full (pointlike and hadronic) fit to the…
The latest CTEQ6.6 parton distributions, obtained by global analysis of hard scattering data in the framework of general-mass perturbative QCD, are employed to study theoretical predictions and their uncertainties for significant processes…
Deconfined strongly interacting QCD matter is produced in the laboratory at the highest energy densities in heavy-ion collisions at the LHC. A selection of recent results from ALICE is presented, spanning observables from the soft sector…
We determine the strong coupling $\alpha_s(m_Z)$ from dimensionless ratios of roots of moments of the charm- and bottom-quark vector and charm pseudo-scalar correlators, dubbed…
A study of the energy dependence of event shape observables is presented. The strong coupling constant \alpha_s has been determined from the mean values of six event shape observables. Power corrections, employed for the measurement of…
We obtain a new value for the QCD coupling constant by combining lattice QCD simulations with experimental data for hadron masses. Our lattice analysis is the first to: 1) include vacuum polarization effects from all three light-quark…
Using data from e+e- annihilation into hadrons, taken with the OPAL detector at LEP at the Z pole between 1991 and 1995, we performed a simultaneous measurement of the colour factors of the underlying gauge group of the strong interaction,…
Since its start of data taking, the LHC has provided an impressive wealth of information on the quark and gluon structure of the proton. Indeed, modern global analyses of parton distribution functions (PDFs) include a wide range of LHC…
A first determination of the strong coupling $\alpha_s(m_Z)$ in next-to-next-to-leading order (NNLO) from inclusive jet and dijet production cross sections in deep-inelastic scattering at HERA is presented. Data collected by the H1…
Precise determinations of the strong coupling constant in hadronic collisions demand sets of parton densities spanning a sufficiently wide range of values for the QCD scale parameter Lambda. For such applications, we supplement the recent…
We compare lattice data for the short-distance part of the static energy in 2+1 flavor quantum chromodynamics (QCD) with perturbative calculations, up to next-to-next-to-next-to leading-logarithmic accuracy. We show that perturbation theory…
We present a new set of parton distributions obtained at NNLO. These differ from the previous sets available at NNLO due to improvements in the theoretical treatment. In particular we include a full treatment of heavy flavours in the region…
Lattice QCD has reached a mature status. State of the art lattice computations include $u,d,s$ (and even the $c$) sea quark effects, together with an estimate of electromagnetic and isospin breaking corrections for hadronic observables.…
We describe the determination of the strong coupling constant $\alpha_s(M_Z^2)$ and of the charm-quark mass $m_c(m_c)$ in the $\bar{\rm MS}$-scheme, based on the QCD analysis of the unpolarized World deep-inelastic scattering data. At NNLO…
Sensitivity to the strong coupling $\alpha_S(M^2_Z)$ is investigated using existing Deep Inelastic Scattering data from HERA in combination with projected future measurements from the Electron Ion Collider (EIC) in a next-to-next-to-leading…
We introduce a model independent method for the determination of the hadronic contribution to the QED running coupling, $\Delta\alpha_{\text{HAD}}(M_{Z}^{2})$, requiring no $e^+e^-$ annihilation data as input. This is achieved by…
We perform the analysis of existing light-targets deep-inelastic-scattering (DIS) data in the leading-order (LO), next-to-leading-order (NLO), and next-to-next-to-leading-order (NNLO) QCD approximations and extract PDFs simultaneously with…
Recent results on jet physics and tests of QCD from hadronic final states in $e^+e^-$ annihilation at PETRA and at LEP are reviewed, with special emphasis on hadronic event shapes, charged particle production rates, properties of quark and…