Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $B_K$ with improved staggered fermions: analysis using SU(2) staggered
  chiral perturbation theory   We report updated results for $B_K$ calculated using HYP-smeared staggered
fermions on the MILC asqtad 2+1 flavor lattices. We use four different lattice
spacings ($a \approx$ 0.12, 0.09, 0.06 and 0.045 fm) to control the continuum
extrapolation. We use SU(2) staggered chiral perturbation theory to do the data
analysis. We find that $B_K(\text{NDR}, \mu=2 \text{GeV}) = 0.526 \pm 0.007 \pm
0.024$ and $\hat{B}_K = B_K(\text{RGI}) = 0.720 \pm 0.010 \pm 0.033$. Here the
first error is statistical and the second systematic. The dominant source of
error is that due to our use of a truncated (one-loop) matching factor.

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The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: econ