Related papers: Calculating $B_K$ using a mixed action
We investigate the effect of non-degenerate quarks on $B_K$. This effect is noticeably large for $B_K$ (significantly larger than statistical uncertainty). Hence, it is important to include this effect in order to determine $B_K$ with…
This talk summarizes the status of the calculations of $B_K$, $B_7$, $B_8$, and $B_s$, done in collaboration with T. Bhattacharya, G. Kilcup, and S. Sharpe. Results for staggered, Wilson, and Clover fermions are presented.
We have computed $ B_K $, using two different methods with staggered fermions on a $ 16^3 \times 40 $ lattice at $ \beta = 5.7 $ with two dynamical flavors of a mass 0.01. % Using an improved wall source method, we have studied a series of…
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…
Last year we proposed using staggered fermions as the light quarks, combined with nonrelativistic heavy quarks, in simulations of heavy-light mesons. A first round of tests which focuses on the B_s meson has been completed using quenched…
We present exploratory results for the hadron mass spectrum and pseudoscalar meson decay constants using mixed actions. We use improved staggered sea quarks and HYP-smeared overlap valence quarks. We obtain good signals on 10 configurations…
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…
We calculate the kaon mixing B-parameters for operators arising generically in theories of physics beyond the standard model. We use HYP-smeared improved staggered fermions on the $N_f = 2+1$ MILC asqtad lattices. Operator matching is done…
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 calculate the kaon B-parameter, B_K, in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We find that the resulting expression is similar to that in…
We calculate one-loop matching factors for bilinear operators composed of improved staggered fermions. We compare the results for different improvement schemes used in the recent literature, including the HYP action and an action close to…
Different versions of improved staggered fermions can be used as valence quarks to reduce discretization effects in lattice QCD calculations while increasing statistics on existing staggered gauge ensembles. Such mixed-action simulations…
We give a progress report on the calculation of B meson mixing matrix elements, focusing on contributions that could arise beyond the Standard Model. The calculation uses asqtad (light quark) and Fermilab (heavy quark) valence actions and…
We present a preliminary calculation of B_K using domain-wall valence quarks and 2+1 flavors of improved staggered sea quarks. Both the size of the residual quark mass, which measures the amount of chiral symmetry breaking, and of the mixed…
We report on a calculation of $B_c$ ground state and radial excitation energies, obtained from heavy-charm highly improved staggered quark (HISQ) correlators computed on MILC gauge ensembles, with lattice spacings down to $a=0.044$ fm.…
We present an update of the Fermilab Lattice and MILC Collaborations project to compute the form factors for semileptonic $B_{(s)}$-meson decays. Our calculation uses the highly improved staggered quark (HISQ) action for sea and valence…
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 present a new action for highly improved staggered fermions. We show that perturbative calculations for the new action are well-behaved where those of the conventional staggered action are badly behaved. We discuss the effects of the new…
We present results for the matrix elements of the additional $\Delta S=2$ operators that appear in models of physics beyond the Standard Model (BSM), expressed in terms of four BSM $B$-parameters. Combined with experimental results for…
We report calculations of B_K using two flavours of dynamical clover-improved Wilson lattice fermions and look for dependence on the dynamical quark mass at fixed lattice spacing. We see some evidence for dynamical quark effects. In…