Related papers: Taste breaking effects in scalar meson correlators
With sufficiently light up and down quarks the isovector ($a_0$) and isosinglet ($f_0$) scalar meson propagators are dominated at large distance by two-meson states. In the staggered fermion formulation of lattice quantum chromodynamics,…
We provide the analytic predictions for the flavor non-singlet scalar correlator, which will enable determination of the scalar meson mass from the lattice scalar correlator. We consider simulations with 2+1 staggered sea quarks and…
Although taste violations significantly affect the results of staggered calculations of pseudoscalar and heavy-light mesonic quantities, those entering staggered calculations of baryonic quantities have not been quantified. Here I develop…
We study taste and Euclidean rotational symmetry violation for staggered fermions at nonzero lattice spacing using staggered chiral perturbation theory. We extend the staggered chiral Lagrangian to O(a^2 p^2), O(a^4) and O(a^2 m), the…
We study the behavior of the isovector scalar correlator, which is particularly sensitive to lattice artifacts, using domain-wall valence quarks on a staggered sea (generated by the MILC collaboration). We analyze this according to the…
Because the propagators of flavor-singlet states incorporate disconnected diagrams, they are uniquely sensitive to any differences in the actions governing sea and valence fermions on the lattice. As such, they present an important test of…
We present a completed random matrix theory for staggered fermions which incorporates all taste symmetry breaking terms at their leading order from the staggered chiral Lagrangian. This is an extension of previous work which only included…
As one test of the validity of the staggered-fermion fourth-root determinant trick, we examine the suppression of the topological susceptibility of the QCD vacuum in the limit of small quark mass. The suppression is sensitive to the number…
In the light pseudoscalar sector, we study rooted staggered chiral perturbation theory in the two-flavor case. The pion mass and decay constant are calculated through NLO for a partially-quenched theory. In the limit where the strange quark…
We present a study of the flavor symmetry breaking in the pion spectrum for various improved staggered fermion actions. To study the effects of link fattening and tadpole improvement, we use three different variants of the p4 action -…
We report on progress in measuring disconnected correlators associated with pseudoscalar flavor-singlet mesons. This will eventually allow us to compute the masses of the eta and eta' mesons. Flavor-singlet physics also presents an…
We discuss the construction of a chiral random matrix model for staggered fermions. This model includes $O(a^2)$ corrections to the continuum limit of staggered fermions and is related to the zero momentum limit of the Lee-Sharpe Lagrangian…
We study the impact of hypercubic (HYP) smearing on the size of taste breaking for staggered fermions, comparing to unimproved and to asqtad-improved staggered fermions. As in previous studies, we find a substantial reduction in…
Staggered fermions with 4 tastes are expected to describe 4-flavor QCD in the continuum limit, therefore at finite lattice spacing the staggered determinant should be equivalent to an SU(4) flavor-symmetric system up to lattice artifacts.…
We study discretization effects in a mixed-action lattice theory with domain-wall valence quarks and Asqtad-improved staggered sea quarks. At the level of the chiral effective Lagrangian, discretization effects in the mixed-action theory…
The topological susceptibility of the vacuum in quantum chromodynamics has been simulated numerically using the Asqtad improved staggered fermion formalism. At nonzero lattice spacing the residual fermion doublers (fermion ``tastes'') in…
We present the current status of the MILC collaboration's calculations of the properties of the light pseudoscalar meson sector. We use asqtad staggered ensembles with 2+1 dynamical flavors down to $a \approx 0.045$ fm and light quark mass…
The recent results by the Fermilab Lattice and MILC collaborations on the hadronic matrix elements entering $B_{d,s}-\bar B_{d,s}$ mixing show a significant tension of the measured values of the mass differences $\Delta M_{d,s}$ with their…
We study the pion spectrum (and in particular taste-symmetry breaking within it) using HYP-smeared valence staggered fermions on the coarse and fine MILC lattices (which have asqtad staggered sea quarks). We focus on the dependence on…
We present recent results from lattice simulations of 2+1 flavors of improved staggered fermions at zero baryon number density near the high temperature crossover. Included are new results from simulations of asqtad fermions at Nt = 12 and…