arXiv subjects

Tian-Shin Guu

Publications and source records attributed to Tian-Shin Guu.

3 recordsLinked to original sources

arXiv2014

Decay Constants of Pseudoscalar $D$-mesons in Lattice QCD with Domain-Wall Fermion

We present the first study of the masses and decay constants of the pseudoscalar $ D $ mesons in two flavors lattice QCD with domain-wall fermion. The gauge ensembles are generated on the $24^3 \times 48 $ lattice with the extent $ N_s = 16 $ in the fifth dimension, and the plaquette gauge action at $ β= 6.10 $, for three sea-quark masses with corresponding pion masses in the range $260-475$ MeV. We compute the point-to-point quark propagators, and measure the time-correlation functions of the pseudoscalar and vector mesons. The inverse lattice spacing is determined by the Wilson flow, while the strange and the charm quark masses by the masses of the vector mesons $ ϕ(1020) $ and $ J/ψ(3097) $ respectively. Using heavy meson chiral perturbation theory (HMChPT) to extrapolate to the physical pion mass, we obtain $ f_D = 202.3(2.2)(2.6) $ MeV and $ f_{D_s} = 258.7(1.1)(2.9) $ MeV.

hep-lat↗

arXiv2011

Lattice QCD with Optimal Domain-Wall Fermion: Light Meson Spectroscopy

We perform lattice simulations of two flavors QCD using the optimal domain-wall fermion, in which the chiral symmetry is preserved to a good precision ($ m_{res} \sim 0.3 $ MeV) on the $ 16^3 \times 32 $ lattice ($ L \sim 2 $ fm) with inverse lattice spacing $ a^{-1} \sim 1.8 $ GeV, and $ N_s = 16 $ in the fifth dimension, for eight sea quark masses corresponding to the pion masses in the range 210-500 MeV. We present our first results of the mass and the decay constant of the pseudoscalar meson, which are in good agreement with the next-to-leading order chiral perturbation theory for $ M_π< 450 $ MeV, and from which we determine the low-energy constants $ f $, $ Σ$, $ \bar{l}_3 $ and $ \bar{l}_4 $. At the physical pion mass $ M_π = 135$ MeV, we obtain the pion decay constant $f_π=133(1)(2)$ MeV, and the average up and down quark mass $m_{ud}^{\bar{\rm MS}}(\mathrm{2 GeV})=4.09(7)(11)$ MeV, where the first error is statistical, and the second error is systematic due to the truncation of the higher order corrections and the uncertainty in the determination of the lattice spacing. Furthermore, we also obtain the chiral condensate $ Σ^{\bar{\mathrm{MS}}}(2 GeV) = [250(4)(7) MeV]^3 $.

hep-lat↗

arXiv2009

TWQCD's dynamical DWF project

We present an overview of our project of simulation of unquenched lattice QCD with optimal domain-wall quarks, using a GPU cluster currently constituting of 16 units of Nvidia Tesla S1070 plus 64 graphic cards with Nvidia GTX285 (total 128 GPUs with 128 Teraflops peak), attaining sustained computing power of 15.36 Teraflops. The first production run in two-flavor QCD is on-going, using the Iwasaki gauge action on a set of lattices with sizes $ 16^3 \times (32,10,8,6,4) \times (16,32) $ at the lattice spacing $ a \sim 0.1$ fm, with eight sea quark masses down to $ m_π\simeq 200 $ MeV. We outline our simulation algorithm, and describe the present status of the production run. Preliminary results of pseudoscalar mass and decay constant are also presented.

hep-lat↗