相关论文: Pion-Nucleon Sigma Term in Lattice QCD
As computing resources are limited, choosing the parameters for a full Lattice QCD simulation always amounts to a compromise between the competing objectives of a lattice spacing as small, quarks as light, and a volume as large as possible.…
We present a study of semi-leptonic $\bar B\tp D\ell\bar\nu$ decays in quenched lattice QCD through a calculation of the matrix element $\la D|\bar c\gamma_\mu b|\bar B\ra$ on a $24^3\times 48$ lattice at $\beta=6.2$, using an…
We present lattice QCD calculations of nucleon electromagnetic form factors using pion masses $m_\pi$ = 149, 202, and 254 MeV and an action with clover-improved Wilson quarks coupled to smeared gauge fields, as used by the…
We report our (HPQCD) progress on the calculation of the Hadronic Vacuum Polarisation contribution to the anomalous magnetic moment of muon. In this article we discuss the calculations for the light (up/down) quark connected contribution…
We present a lattice QCD calculation of the form factors and differential decay rates for semileptonic decays of the heavy-light mesons $B$ and $D$ to the final state $\pi l\nu$. The results are obtained with three methodological…
In this work, we present a first-principles lattice-QCD calculation of the unpolarized quark PDF for the pion and the kaon. The lattice data rely on matrix elements calculated for boosted mesons coupled to non-local operators containing a…
We report on a lattice QCD calculation of the nucleon axial charge, $g_A$, using M\"{o}bius Domain-Wall fermions solved on the dynamical $N_f=2+1+1$ HISQ ensembles after they are smeared using the gradient-flow algorithm. The calculation is…
We calculate the "strange quark content of the nucleon", <N| s s_bar |N>, which is important for interpreting the results of some dark matter detection experiments. The method is to evaluate quark-line disconnected correlations on the MILC…
We evaluate the $\Lambda_c\Sigma_c\pi$ coupling constant ($G_{\Lambda_c \Sigma_c \pi}$) and the width of the strong decay $\Sigma_c \rightarrow\Lambda_c \pi$ in 2+1 flavor lattice QCD on four different ensembles with pion masses ranging…
The investigation of light sea-quark effects in lattice QCD with dynamical Wilson fermions requires both larger physical volumes and finer lattice resolutions than achieved previously. As high-end supercomputers like the 512-node APE Tower…
We calculate $p\Xi^0$ potentials from the equal-time Bethe-Salpeter amplitude measured in the quenched QCD simulation with the spatial lattice volume, (4.4 fm)$^3$. The standard Wilson gauge action with the gauge coupling $\beta=5.7$ on…
We present results for the iso-vector and flavor diagonal tensor charges $g^{u-d}_T$, $g^{u}_T$, $g^{d}_T$, and $g^{s}_T$ needed to probe novel tensor interactions at the TeV scale in neutron and nuclear $\beta$-decays and the contribution…
The problem of unphysical zero modes in lattice QCD with Wilson fermions can be solved in a clean way by including a mass term proportional to $i \psibar \gamma_5 \tau^3 \psi$ in the standard lattice theory with Nf=2 mass degenerate Wilson…
We derive the asymptotic lattice spacing dependence $a^n[2b_0\bar{g}^2(1/a)]^{\hat{\Gamma}_i}$ relevant for spectral quantities of lattice QCD, when using Wilson, O$(a)$ improved Wilson or Ginsparg-Wilson quarks. We give some examples for…
The nucleon-pion-state contribution to QCD two-point and three-point functions relevant for lattice calculations of the nucleon electromagnetic form factors are studied in chiral perturbation theory. To leading order the results depend on a…
We report on preliminary results of a high statistics quenched lattice QCD calculation of nucleon matrix elements within the Symanzik improvement programme. Using the recently determined renormalisation constants from the Alpha…
We present the first chiral-continuum extrapolated up, down and strange quark spin contribution to the proton spin using lattice QCD. For the connected contributions, we use eleven ensembles of 2+1+1-flavor of Highly Improved Staggered…
Lattice formulations of QCD with Wilson fermions and a chirally twisted quark mass matrix provide an attractive framework for non-perturbative numerical studies. Owing to reparameterization invariance, the limiting continuum theory is just…
We calculate the nucleon and the delta mass to fourth order in a covariant formulation of the small scale expansion. We analyze lattice data from the MILC collaboration and demonstrate that the available lattice data combined with our…
We report an exploratory lattice investigation of $\sigma$ meson decay width using s-wave scattering phase for isospin I=0 pion-pion ($\pi\pi$) system. Rummukainen-Gottlieb formula is used to estimate the scattering phase, which demonstrate…