Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong-Isospin Violation in the Neutron-Proton Mass Difference from
  Fully-Dynamical Lattice QCD and PQQCD   We determine the strong-isospin violating component of the neutron-proton
mass difference from fully-dynamical lattice QCD and partially-quenched QCD
calculations of the nucleon mass, constrained by partially-quenched chiral
perturbation theory at one-loop level. The lattice calculations were performed
with domain-wall valence quarks on MILC lattices with rooted staggered
sea-quarks at a lattice spacing of b=0.125 fm, lattice spatial size of L=2.5 fm
and pion masses ranging from m_pi ~ 290 MeV to ~ 350 MeV. At the physical value
of the pion mass, we predict M_n - M_p |(d-u) = 2.26 +- 0.57 +- 0.42 +- 0.10
MeV where the first error is statistical, the second error is due to the
uncertainty in the ratio of light-quark masses, eta=m_u/m_d, determined by
MILC, and the third error is an estimate of the systematic due to chiral
extrapolation.

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The categories of this paper are: cs
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The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: astro-ph
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph