Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strange quark contributions to nucleon mass and spin from lattice QCD   Contributions of strange quarks to the mass and spin of the nucleon,
characterized by the observables f_Ts and Delta s, respectively, are
investigated within lattice QCD. The calculation employs a 2+1-flavor
mixed-action lattice scheme, thus treating the strange quark degrees of freedom
in dynamical fashion. Numerical results are obtained at three pion masses, m_pi
= 495 MeV, 356 MeV, and 293 MeV, renormalized, and chirally extrapolated to the
physical pion mass. The value extracted for Delta s at the physical pion mass
in the MSbar scheme at a scale of 2 GeV is Delta s = -0.031(17), whereas the
strange quark contribution to the nucleon mass amounts to f_Ts =0.046(11). In
the employed mixed-action scheme, the nucleon valence quarks as well as the
strange quarks entering the nucleon matrix elements which determine f_Ts and
Delta s are realized as domain wall fermions, propagators of which are
evaluated in MILC 2+1-flavor dynamical asqtad quark ensembles. The use of
domain wall fermions leads to mild renormalization behavior which proves
especially advantageous in the extraction of f_Ts.

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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: chem-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: astro-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
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The categories of this paper are: nlin
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The categories of this paper are: nucl-ex