Light hadron spectroscopy using domain wall valence quarks on an asqtad sea

Abstract

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 ≈ 2.5 fm, and a lattice spacing of a ≈ 0.124 fm, for pion masses as light as mπ ≈ 300 MeV, and compared with the results by the MILC collaboration with Asqtad valence quarks at the same lattice spacing. Two-and three-flavor chiral extrapolations of the baryon masses are performed using both continuum and mixed-action heavy baryon chiral perturbation theory. Both the threeflavor and two-flavor functional forms describe our lattice results, although the low-energy constants from the next-to-leading order SU (3) fits are inconsistent with their phenomenological values. Nextto-next-to-leading order SU (2) continuum formulae provide a good fit to the data and yield and extrapolated nucleon mass consistent with experiment, but the convergence pattern indicates that even our lightest pion mass may be at the upper end of the chiral regime. Surprisingly, our nucleon masses are essentially lineaer in mπ over our full range of pion masses, and we show this feature is common to all recent dynamical calculations of the nucleon mass. The origin of this linearity is not presently understood, and lighter pion masses and increased control of systematic errors will be needed to resolve this puzzling behavior.

S-waveKK*interactions in a finite volume and thefGeng1, Ren2, Zhou3 et al. 2015Phys. Rev. D292330View full textAdd to dashboardCite

“…The ground-state pseudoscalar mesons and vector mesons have been studied in a number of n f = 2 + 1 LQCD simulations [57][58][59][60][61]. Some of the gauge configurations are available on the International Lattice Data Grid, e.g., the PACS-CS configurations [58], which in principle makes a study of the f 1 (1285) straightforward.…”

Baryons as relativistic three-quark bound states

“…In lattice QCD as well as in the functional framework, the current-quark masses appearing in the Lagrangian of QCD are input parameters and may be tuned at will. As discussed above, lattice calculations become prohibitively more expensive for small quark masses and therefore current-mass evolutions have been frequently used in the past to perform chiral extrapolations to the physical point [265,396,[402][403][404]. In recent years, simulations at or close to the physical point have become available due to increasing computer power and improved algorithms [405].…”

One-loop analysis of the interactions between charmed mesons and Goldstone bosons

“…Since the same ensembles are employed in ref. [48], we take the data for f π and f K from ref. [48], where f π = √ 2F π and f K = √ 2F K .…”

“…[48], we take the data for f π and f K from ref. [48], where f π = √ 2F π and f K = √ 2F K . Those lattice data are well described as shown in figure 3 10 when the parameters take the values given in table 3.…”

“…9 The mass of the η is always expressed in terms of Mπ and MK through the Gell-Mann-Okubo mass 10 We have neglected the subtleties due to the use of mixed action gauge configurations in the lattice calculations, which in principle requires to use the partially quenched ChPT instead of the standard one for the chiral extrapolation, and the effect of finite lattice spacing, see ref. [48].…”