Related papers: Systematic Uncertainties in $B_K$ with Improved St…
The phase diagram for staggered fermions is discussed in the context of the staggered chiral Lagrangian, extending previous work on the subject. When the discretization errors are significant, there may be an Aoki-like phase for staggered…
We present improved results for the B and D meson spectrum from lattice QCD including the effect of u/d,s and c quarks in the sea. For the B mesons the Highly Improved Staggered Quark action is used for the sea and light valence quarks and…
We calculate the B-meson decay constants f_B, f_Bs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b-quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the…
We present the first step towards the estimation of finite volume effects in heavy-light meson systems using heavy meson chiral perturbation theory. We demonstrate that these effects can be amplified in both light-quark and heavy-quark mass…
During the last years, the ALPHA collaboration has been developing and implementing a method based on Heavy Quark Effective Theory (HQET) to compute B-mesons observables through lattice simulations. Thanks to a non-perturbative matching to…
We calculate the fermion self-energy at O(alpha_s) for the Symanzik improved staggered fermion action used in recent lattice simulations by the MILC collaboration. We demonstrate that the algebraic approach to lattice perturbation theory,…
We investigate the use of two types of non-local (``smeared'') sources for quark propagators in quenched lattice QCD at $\beta=6.0$ using Wilson fermions at $\kappa=0.154$ and $0.155$. We present results for the hadron mass spectrum, meson…
In order to study the QCD chiral critical point we investigate Binder Cumulants of the chiral condensate. The results were obtained from simulations of 3 and 2+1 flavors of standard staggered fermions and 3 flavors of p4 improved staggered…
We have simulated QCD using 2+1 flavors of domain wall quarks on a $(2.74 {\rm fm})^3$ volume with an inverse lattice scale of $a^{-1} = 1.729(28)$ GeV. The up and down (light) quarks are degenerate in our calculations and we have used four…
We compute pseudoscalar meson masses and decay constants in partially quenched QCD with three dynamical flavors of improved staggered quarks. Fitting the lattice data to staggered chiral perturbation theory forms and extrapolating in quark…
The decays $B_d\to\pi^\mp K^\pm$ and $B^\pm\to\pi^\pm K$ provide interesting constraints on the angle $\gamma$ of the unitarity triangle of the CKM matrix. It is shown that bounds on $\gamma$ can also be obtained from the time evolution of…
We calculate the light hadron spectrum in full QCD using two plus one flavor Asqtad sea quarks and domain wall valence quarks. Meson and baryon masses are calculated on a lattice of spatial size $L \approx 2.5$\texttt{fm}, and a lattice…
We present results for the hadron spectrum and static quark potential from a simulation with two flavours of $O(a)$ improved dynamical Wilson fermions at $\beta=5.2$. We address the issues of sea quark dependence of observables and…
Since b quark mass is not asymptotically large, chirally enhanced corrections which arise from twist-3 wave functions may be important in B decays. We thus evaluate the hadronic matrix elements with the emitted meson described by leading…
We present results for the light quark masses and the neutral kaon mixing parameter $B_K$ from lattice QCD. Our data set includes lighter than physical light quark masses and 5 lattice spacings so that chiral extrapolation is not necessary…
Recent results for the spectrum of light hadrons provide clear evidence for the failure of quenched QCD and encouraging signs that simulations with dynamical sea quarks rectify some of the discrepancies, although string breaking has not yet…
We report on the status of the Fermilab-MILC calculation of the form factor f_+^{K pi}(0), needed to extract the CKM matrix element |V_{us}| from experimental data on K semileptonic decays. The HISQ formulation is used in the simulations…
We calculate the form factor f_+(q^2) for B-meson semileptonic decay in unquenched lattice QCD with 2+1 flavors of light sea quarks. We use Asqtad-improved staggered light quarks and a Fermilab bottom quark on gauge configurations generated…
Staggered fermion shift symmetries correspond to translations of the fermion field within the unit cell of a hypercubic lattice. They satisfy an algebra and in four Euclidean dimensions can be related to a discrete subgroup of an $SU(4)$…
We deliver the realistic ab initio lattice investigations of $K \overline{K}$ scattering. In the Asqtad-improved staggered dynamical fermion formulation, we carefully measure $K\overline{K}$ four-point function in the $I=0$ channel by…