Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pion Form Factor in Improved Holographic QCD Backgrounds   We extend a recent numerical calculation of the pion electromagnetic form
factor F_\pi (Q^2) in holographic QCD to study two important issues regarding
the behavior of fields in the bulk. First, we show that using a chiral
symmetry-breaking field formally satisfying the boundary conditions of the
``soft-wall'' model changes numerical results very little from the earlier
calculation that ignores these constraints. Second, we use a background field
that interpolates between ``hard-wall'' and ``soft-wall'' models to obtain an
improved model that reproduces the desirable phenomenological features of both.
In all cases, F_\pi$ for large Q^2 is shallower than data, an effect that can
be cured by relaxing the fit to one of the static observables, particularly the
decay constant f_\pi.

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The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
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The categories of this paper are: comp-gas
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn