相关论文: Precise determination of $\alpha_s$ from relativis…
We briefly review how precise determinations of the strong coupling constant and of the heavy quark masses may be obtained from heavy quarkonium. Such determinations are competitive with heavy quark masses extraction from other systems and…
We report on an estimate of \alpha_s, renormalised in the MSbar scheme at the tau and Z^0 mass scales, by means of lattice QCD. Our major improvement compared to previous lattice calculations is that, for the first time, no perturbative…
Recent theoretical and experimental improvements in the determination of charm and bottom quark masses are discussed. The final results, $m_c(3 \text{GeV})=986(13) $MeV and $m_b(m_b)=4163(16) $MeV represent, together with a closely related…
The determination of the charm quark mass is now possible to 1% from QCD, with lattice QCD pushing the error down below 1%. I will describe the ingredients of this approach and how it can achieve this accuracy. Results for quark mass…
We present preliminary results for the charm quark mass $m_c$ and the $D$ and $D_s$ mesons decay constants $f_D$ and $f_{D_s}$ from a lattice QCD calculation with ${\rm N_f}$ = 2 dynamical fermions. We use the twisted mass fermionic action…
In this work the charm and bottom quark masses are determined from QCD moment sum rules for the charmonium and upsilon systems. In our analysis we include both the results from non-relativistic QCD and perturbation theory at…
We present a determination of the strong coupling $\alpha_s(m_Z)$ from a global dataset including both fixed-target and collider data from deep-inelastic scattering and a variety of hadronic processes, with a simultaneous determination of…
The effects of the finite charm quark mass on bottom quark mass determinations from $\Upsilon$ sum rules are examined in detail. The charm quark mass effects are calculated at next-to-next-to-leading order in the non-relativistic power…
Recent calculations of supersymmetric corrections to the conflicting ratios $R_b$ and $R_c$ have shown that an alleged discrepancy between the SM predictions of these observables and the corresponding experimental values can be cured in the…
We present a new dispersive framework for the extraction of the strong coupling constant $\alpha_s$ from $\tau$-lepton decays. A new feature of our procedure is the use of the quark-hadron duality on the limited region $s_{\rm…
We present an analysis to determine the charm quark mass from non-relativistic sum rules, using a combined approach taking into account fixed-order and effective-theory calculations. Non-perturbative corrections as well as higher-order…
The standard determination of the QED coupling on the Z pole is performed using the latest available data for R. The direct application of analytic continuation techniques is found not to improve the accuracy of the value of \alpha(M_Z^2).…
We formulate lattice fermions in a way that encompasses Wilson fermions as well as the static and non-relativistic approximations. In particular, we treat $m_qa$ systematically ($m_q$ is the fermion mass) showing how to understand the…
Using a new result for the first moment of the hadronic production cross section at order ${\cal O}(\alpha_s^3)$, and new data on the $J/\psi$ and $\psi'$ resonances for the charm quark, we determine the \msb masses of the charm and bottom…
The parametric error on the QCD-coupling can be a dominant source of uncertainty in several important observables. One way to extract the coupling is to compare high order perturbative computations with lattice evaluated moments of heavy…
We compute the fermionic contribution to the strong coupling $\alpha_{qq}$ extracted from the static force in Lattice QCD up to order $g^4$ in perturbation theory. This allows us to subtract the leading fermionic lattice artifacts from…
The finite energy sum rule extraction of the strong coupling {\alpha}_s from hadronic {\tau} decay data provides one of its most precise experimental determinations. As precision improves, small non-perturbative effects become increasingly…
We investigate the charm quark system using the relativistic heavy quark action on 2+1 flavor PACS-CS configurations previously generated on $32^3 \times 64$ lattice. The dynamical up-down and strange quark masses are set to the physical…
We determine the strong coupling constant $\alpha_s$ from the static QCD potential by matching a theoretical calculation with a lattice QCD computation. We employ a new theoretical formulation based on the operator product expansion, in…
We compute the decoupling relations for the strong coupling, the light quark masses, the gauge-fixing parameter, and the light fields in QCD with heavy charm and bottom quarks to three-loop accuracy taking into account the exact dependence…