Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: QCD Sum-Rule Consistency of Lowest-Lying Quark Scalar Resonances   We investigate lowest-lying scalar meson properties predicted from QCD
Laplace sum rules based upon isovector and isoscalar non-strange $\bar{q}q$
currents. The hadronic content of these sum rules incorporates deviations from
the narrow resonance approximation anticipated from physical resonance widths.
The field theoretical content of these sum rules incorporates
purely-perturbative QCD contributions to three-loop order, the direct
single-instanton contribution in the instanton liquid model, and leading
contributions from QCD-vacuum condensates. In the isovector channel, the
results we obtain are compatible with a$_0$(1450) being the lowest-lying
$q\bar{q}$ resonance, and are indicative of a non-$q\bar{q}$ interpretation for
a$_0$(980). In the isoscalar channel, the results we obtain are compatible with
the lowest lying $q\bar{q}$ resonance being f$_0$(980) or a state somewhat
lighter than f$_0$(980) whose width is less than half of its mass. The dilaton
scenario for such a narrower $\sigma$-resonance is discussed in detail, and is
found compatible with sum rule predictions for the resonance coupling only if
the anomalous gluon-field portion of $\Theta_\mu^\mu$ dominates the matrix
element $<\sigma|\Theta_\mu^\mu|0>$. A linear sigma-model interpretation of the
lowest-lying resonance's coupling, when compared to the coupling predicted by
sum rules, is indicative of a renormalization-group invariant light-quark mass
between 4 and 6 MeV.

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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: physics
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-lat