Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pion form factor at spacelike momentum transfers from local-duality QCD
  sum rule   We study the pion form factor in a broad range of spacelike momentum
transfers within the local-duality version of QCD sum rules. We make use of the
recently calculated two-loop double spectral density of the $<AVA>$ correlator
including O(1) and $O(\alpha_s)$ terms, which allows us to give predictions for
the pion form factor and to study the interplay between the nonperturbative and
perturbative contributions to the pion form factor without any reference to the
pion distribution amplitude. Our results demonstrate the dominance of the
nonperturbative contribution to the form factor up to relatively large values
of the momentum transfer: namely, the nonperturbative O(1) term, which provides
the $1/Q^4$ power correction, gives more than half of the pion form factor in
the region $Q^2 \le 20$ GeV$^2$.

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The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org