Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 2+1 Flavor Lattice QCD toward the Physical Point   We present the first results of the PACS-CS project which aims to simulate
2+1 flavor lattice QCD on the physical point with the nonperturbatively
$O(a)$-improved Wilson quark action and the Iwasaki gauge action. Numerical
simulations are carried out at the lattice spacing of $a=0.0907(13)$fm on a
$32^3\times 64$ lattice with the use of the DDHMC algorithm to reduce the
up-down quark mass. Further algorithmic improvements make possible the
simulation whose ud quark mass is as light as the physical value. The resulting
PS meson masses range from 702MeV down to 156MeV, which clearly exhibit the
presence of chiral logarithms. An analysis of the PS meson sector with SU(3)
ChPT reveals that the NLO corrections are large at the physical strange quark
mass. In order to estimate the physical ud quark mass, we employ the SU(2)
chiral analysis expanding the strange quark contributions analytically around
the physical strange quark mass. The SU(2) LECs ${\bar l}_3$ and ${\bar l}_4$
are comparable with the recent estimates by other lattice QCD calculations. We
determine the physical point together with the lattice spacing employing
$m_\pi$, $m_K$ and $m_\Omega$ as input. The hadron spectrum extrapolated to the
physical point shows an agreement with the experimental values at a few % level
of statistical errors, albeit there remain possible cutoff effects. We also
find that our results of $f_\pi=134.0(4.2)$MeV, $f_K=159.4(3.1)$MeV and
$f_K/f_\pi=1.189(20)$ with the perturbative renormalization factors are
compatible with the experimental values. For the physical quark masses we
obtain $m_{\rm ud}^\msbar=2.527(47)$MeV and $m_{\rm s}^\msbar=72.72(78)$MeV
extracted from the axial-vector Ward-Takahashi identity with the perturbative
renormalization factors.

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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: cs
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph