相关论文: Unquenched QCD with Light Quarks
We explain how scale dependent renormalized quantities can be computed using lattice QCD. Two examples are used: the running coupling and quark masses. A reliable computation of the $\Lambda$-parameter in the quenched approximation is…
We present a summary of our results for the light hadron spectrum in quenched lattice QCD and preliminary ones in two-flavor full QCD. For the quenched hadron spectrum we find that the mass formulae predicted by quenched chiral perturbation…
We present results of a large-scale simulation for the flavor non-singlet light hadron spectrum in quenched lattice QCD with the Wilson quark action. Hadron masses are calculated at four values of lattice spacing in the range $a \approx$…
As part of our program of lattice simulations of three flavor QCD with improved staggered quarks, we have calculated pseudoscalar meson masses and decay constants for a range of valence quark masses and sea quark masses on lattices with…
A recently developed model for the QCD analytic invariant charge is compared with quenched lattice simulation data on the static quark-antiquark potential. By employing this strong running coupling one is able to obtain the confining…
We search for possibly existent bound states in the heavy-light tetraquark channels with quark content $ \bar{b}\bar{b}ud $, $ \bar{b}\bar{b}us $ and $ \bar{b}\bar{c}ud $ using lattice QCD. We carry out calculations on several gauge link…
We determine the strange quark condensate from lattice QCD for the first time and compare its value to that of the light quark and chiral condensates. The results come from a direct calculation of the expectation value of the trace of the…
We calculate the heavy-light meson decay constant using lattice NRQCD action for the heavy quark and Wilson quark action for the light quark over a wide range in the heavy quark mass. Simulations are carried out on a 16^3 x 32 lattice with…
We compute the static-light meson spectrum with N_f = 2 flavours of sea quarks using Wilson twisted mass lattice QCD. We consider five different values for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV and we present…
The perturbative expression of the running strong coupling constant \alpha_{\rm s}(Q^{2}) has an unphysical singularity for Q^{2} = \Lambda^{2}_{\rm QCD}. Various modification have been proposed for the infrared region. The effect of some…
The QCD-coupling is a necessary input in the computation of many observables, and the parametric error on input parameters can be a dominant source of uncertainty. The coupling can be extracted by comparing high order perturbative…
We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N_f = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark…
The concept of simulating a variant of QCD with sea quarks which interact with the gluon configuration only via global gluonic quantities like $\int F\tilde F dx$ and $\int FF dx$ is tested for the case of the massive 2-flavour Schwinger…
The effect of sea quark electromagnetic charge on meson masses is investigated, and first results for full QED+QCD low-energy constants are presented. The electromagnetic charge for sea quarks is incorporated in quenched QED+full QCD…
The light quark results from three different simulations are summarized. We get consistent results, within our statistics, between smeared and non smeared data. A comparison is performed with similar results from the UKQCD collaboration.…
The light quark masses are determined using a new QCD Finite Energy Sum Rule (FESR) in the pseudoscalar channel. This FESR involves an integration kernel designed to reduce considerably the contribution of the (unmeasured) hadronic…
We present the results of our lattice QCD computation of the hadronic matrix elements relevant to the $h_{c}\to \eta_{c}\gamma$ and $h_{b}\to \eta_{b}\gamma$ decays by using the gauge configurations produced by the Extended Twisted Mass…
We present a preliminary analysis of the heavy-heavy spectrum and heavy-light decay constants in full QCD, using a tadpole-improved SW quark action and an RG-improved gauge action on a 16^3 x 32 lattice with four sea quark masses…
Temporal quark correlation functions are analyzed in quenched lattice QCD for two values of temperature above the critical temperature (Tc) for deconfinement, T=1.5Tc and 3Tc. A two-pole ansatz for the quark spectral function is used to…
Simulations that use the clover action in quenched QCD calculations have a lower limit to the quark mass that can be reached, because of the fluctuations caused by exceptional configurations. From this low statistics study, we find that the…