Related papers: Hopping Parameter Expansion for Heavy-Light System…
We introduce and study the properties of the "color-straight" four-quark operators containing heavy and light quark fields. They are of the form (\bar b\Gamma_b b)(\bar q\Gamma_q q) where both brackets are color singlets. Their expectation…
We present preliminary results for heavy to light transitions of pseudoscalar mesons, induced by the vector and tensor operators. This lattice study is performed in quenched approximation, by using the nonperturbatively improved Wilson…
We review the technique of heavy quark mass expansion of various operators made of heavy quark fields using a semiclassical approximation. It corresponds to an operator product expansion in the form of series in the inverse heavy quark…
The masses and vertex functions of heavy and heavy-light mesons, described as quark-antiquark bound states, are calculated with the Covariant Spectator Theory (CST). We use a kernel with an adjustable mixture of Lorentz scalar,…
The masses of the ground state heavy baryons consisting of two light (u,d,s) and one heavy (c,b) quarks are calculated in the heavy-quark--light-diquark approximation within the constituent quark model. The light quarks, forming the…
We describe the effective heavy meson lagrangian for S- and P-wave heavy-light mesons in terms of a model based on meson-quark interactions, where mesonic transition amplitudes are represented by diagrams with heavy mesons attached to loops…
We generalize the celebrated heavy quark expansion to nonlocal QCD operators. By taking nonlocal heavy-light current on the light-cone as an example, we confirm that the collinear singularities are common between QCD operator and the…
We determine the light quark masses from lattice QCD simulations incorporating the electromagnetic interaction of valence quarks. The meson masses are calculated on lattice QCD configurations generated by the RBC Collaboration for two…
We report on the status of an update of our collaboration's previous computation of light and strange quark masses in QCD with $N_{f}=2+1$ dynamical flavours. Bare quark masses are extracted from CLS ensembles, using $O(a)$-improved Wilson…
We compute ratios between the vector and pseudoscalar, and tensor and vector decay constants, and between hyperfine splittings for $D_{(s)}^{(*)}$ and $B_{(s)}^{(*)}$ mesons. We use the Highly Improved Staggered Quark (HISQ) action for all…
We compute the decay constants for the heavy--light pseudoscalar mesons in the quenched approximation and continuum limit of lattice QCD. Within the Schrodinger Functional framework, we make use of the step scaling method, which has been…
Within the framework of the quark model and the variational method, the bound states of four heavy quarks (tetraquarks) are investigated. The basis variational wave functions are chosen in the Gaussian form. The matrix elements of the…
Using the Janik-Peschanski dual to a Bjorken flow, a Langevin equation is derived for a heavy quark in an expanding N = 4 supersymmetric Yang-Mills plasma. Such a plasma is characterized by a proper-time dependence of the temperature and…
Using a method previously developed, based on the Mellin-Barnes transform, we reconstruct the two-point correlators in the vector, axial, scalar and pseudoscalar channels from the Taylor expansion at q^2=0, the threshold expansion at…
We propose a method to improve lattice operators composed of Wilson fermions which allows the removal of all corrections of $O(a)$, including those proportional to the quark mass, leaving only errors of $O(a^2)$. The method exploits the…
The status of lattice calculations for heavy quark systems is reviewed, focussing on weak matrix elements for leptonic and semi-leptonic decays of heavy mesons. After an assessment of the main systematic errors, results for the decay…
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…
We describe recent results concerning the behavior of lattice QCD with light dynamical Wilson and Staggered quarks. We show that it is possible to reach regions of parameter space with light pions $m_\pi\approx 0.2/a$ using Wilson fermions.…
We present estimates of light quarks masses using lattice data. Our main results are based on a global analysis of all the published data for Wilson and Staggered fermions, both in the quenched approximation and with $n_f=2$ dynamical…
The perturbative QCD fragmentation functions for a heavy quark to fragment into heavy-light mesons are studied in the heavy-quark limit. The fragmentation functions for S-wave pseudoscalar and vector mesons are calculated to next-to-leading…