Related papers: Dynamical determination of B_K from improved stagg…

We compare calculations of B_K with improved staggered quarks (HYP, Asqtad) and demonstrate the improved scaling behaviour that this gives rise to over previous calculations with unimproved staggered quarks. This enables us to perform the…

The use of improved staggered actions (HYP, Asqtad) has been proved to reduce the scaling corrections that affected previous calculations of B_K with unimproved (standard) staggered fermions in the quenched approximation. This improved…

We present the results for $B_K$ calculated using HYP-smeared staggered fermions using lattices generated by the MILC collaboration using the asqtad staggered action. We have done the calculation on 8 ensembles of these lattices, including…

We give an update on our calculation of $B_K$ using HYP-smeared valence staggered quarks. We have results for $B_K$ at tree-level on several coarse MILC lattices ($a\approx 0.12 $fm) and one of the fine lattices ($a\approx 0.09 $fm), using…

We update our results for $B_K$ obtained using HYP-smeared staggered valence quarks on the MILC asqtad lattices. In the last year, we have added 5 new measurments on the fine ($a\approx 0.09\;$fm) ensembles, and 2 new measurements on the…

We present updated results for kaon B-parameters for operators arising in models of new physics. We use HYP-smeared staggered quarks on the $N_f = 2+1$ MILC asqtad lattices. During the last year we have added new ensembles, which has…

We present preliminary results of $B_K$ calculated using improved staggered fermions with the mixed action (valence quarks = HYP staggered fermions and sea quarks = AsqTad staggered fermions). We analyze the data based upon the prediction…

We present preliminary results for $B_K$ calculated using improved staggered fermions with a mixed action (HYP-smeared staggered valence quarks and AsqTad staggered sea quarks). We investigate the effect of non-degenerate quarks on $B_K$…

We present an update for results on $B$-meson semileptonic decays using the highly improved staggered quark (HISQ) action for both valence and 2+1+1 sea quarks. The use of the highly improved action, combined with the MILC collaboration's…

The improved staggered quark action has enabled breakthrough calculations of QCD with three light dynamical quarks. The largest remaining $a^2$ scaling violations come from "taste-changing" interactions, which are significantly reduced over…

We present results for kaon mixing parameter $B_K$ calculated using HYP-smeared improved staggered fermions on the MILC asqtad lattices. We use three lattice spacings ($a\approx 0.12$, $0.09$ and $0.06\;$fm), ten different valence quark…

We report on recent progress in the calculation of $B_K$ using HYP-smeared improved staggered fermions on the MILC asqtad lattices. We have added measurements on fine ($a\sim 0.09 $fm) and superfine ($a\sim 0.06 $fm) ensembles at different…

We report on results from three spectrum calculations with staggered quarks: 1) a quenched calculation with the standard action for the gluons and quarks; 2) a quenched calculation with improved actions for both the gluons and quarks; and…

We report updated results for $B_K$ calculated using HYP-smeared staggered fermions on the MILC asqtad 2+1 flavor lattices. We use four different lattice spacings ($a \approx$ 0.12, 0.09, 0.06 and 0.045 fm) to control the continuum…

We calculate the kaon B-parameter, B_K, to next-to-leading order in staggered chiral perturbation theory. We find expressions for partially quenched QCD with three sea quarks, quenched QCD, and full QCD with m_u = m_d but not equal to m_s.…

We study three sources of error in our calculation of $B_K$ using HYP-smeared staggered fermions on the MILC asqtad lattices. These are (1) dependence on the light sea quark mass; (2) finite volume effects; and (3) the impact of an order of…

We report on recent progress in employing the Highly Improved Staggered Quark (HISQ) action introduced by the HPQCD/UKQCD collaboration in simulations with dynamical fermions. The HISQ action is an order $a^2$ Symanzik-improved action with…

We report updated results for $B_K$ using HYP-smeared staggered valence quarks on MILC asqtad lattices based on an analysis using SU(3) staggered chiral perturbation theory. The most important new feature of our data sample is the inclusion…

We compute Z-factors for general staggered bilinears on fine (a \approx 0.09 fm) MILC ensembles using both asqtad and HYP-smeared valence actions, comparing the results to the predictions of one-loop perturbation theory. This is an…

We resolve contradictions in the literature concerning the origins and size of unphysical flavor-changing strong interactions generated by the staggered-quark discretization of QCD. We show that the leading contributions are tree-level in…