相关论文: Scalar Meson Spectroscopy with Lattice Staggered F…
As a consistency check of the staggered-fermion fourth-root approximation, we analyze the a_0 and f_0 correlators, including the effects of two-meson taste-multiplet intermediate states. Rooted staggered chiral perturbation theory describes…
The Asqtad improved staggered fermion formalism has been a valuable tool in successfully calculating the non-singlet parts of the hadronic spectrum. We are engaged in a project to calculate the spectrum of the pseudoscalar singlet mesons…
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 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 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…
Using the lattice simulations in the Asqtad-improved staggered fermion formulation we compute the point-to-point $\kappa$ correlators, which are analyzed by the rooted staggered chiral perturbation theory (rS$\chi$PT). After chiral…
Accurately calculating the mass of flavor-singlet meson states from numerical lattice simulations is an important milestone for lattice QCD. Careful measurement of the full pseudoscalar flavor-singlet propagator is also a crucial step in…
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 present the first 2+1 flavour lattice QCD calculations of pseudoscalar flavour-singlet propagators using improved staggered fermions. We explore the relevant techniques and discuss prospects for the larger scale studies now in progress.…
To investigate the viability of the 4th root trick for the staggered fermion determinant in a simpler setting, we consider a two taste (flavor) lattice fermion formulation with no taste mixing but with exact taste-nonsinglet chiral…
We present some early results from a high statistics study of the scalar and pseudoscalar singlet sectors of lattice QCD using 2+1 flavours of Asqtad improved staggered fermions. The use of the Asqtad action has allowed us to generate an…
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…
The results of a high-statistics study of scalar and pseudoscalar meson propagators in quenched lattice QCD are presented. For two values of lattice spacing, $\beta=5.7$ ($a \approx .18$ fm) and 5.9 ($a \approx .12$ fm), we probe the light…
Staggered chiral perturbation theory (schpt) takes into account the "fourth-root trick" for reducing unwanted (taste) degrees of freedom with staggered quarks by multiplying the contribution of each sea quark loop by a factor of 1/4. In the…
Many results from lattice QCD of broad importance to particle and nuclear physics are obtained with 2+1 flavors of staggered sea quarks. In the continuum limit, staggered fermions yield four species, called tastes. To reduce the number of…
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…
We present a scaling study of the QCD spectrum using a smeared P4 staggered fermion formulation, in which three, five, and seven-link staples are added to reduce the effects of flavor symmetry breaking. These studies are performed on…
We study the $\kappa$ meson in 2+1 flavor QCD with sufficiently light $u/d$ quarks. Using numerical simulation we measure the point-to-point $\kappa$ correlators in the "Asqtad" improved staggered fermion formulation. We analyze those…
We introduce a class of improved actions for staggered fermions which to O(p^4) and O(p^6), respectively, lead to rotationally invariant propagators. We discuss the resulting reduction of flavour symmetry breaking in the meson spectrum and…
In HISQ simulations by the MILC and Fermilab Lattice collaborations, both the light quarks and the charm quark are staggered. We extend staggered chiral perturbation theory (\schpt) to include such all-staggered heavy-light mesons. We…