Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Contribution of the $a_1$ meson to the axial nucleon-to-$\Delta$
  transition form factors   We analyze the low-$Q^2$ behavior of the axial form factor $G_A(Q^2)$, the
induced pseudoscalar form factor $G_P(Q^2)$, and the axial nucleon-to-$\Delta$
transition form factors $C^A_5(Q^2)$ and $C^A_6(Q^2)$. Building on the results
of chiral perturbation theory, we first discuss $G_A(Q^2)$ in a chiral
effective-Lagrangian model including the $a_1$ meson and determine the relevant
coupling parameters from a fit to experimental data. With this information, the
form factor $G_P(Q^2)$ can be predicted. For the determination of the
transition form factor $C^A_5(Q^2)$ we make use of an SU(6) spin-flavor
quark-model relation to fix two coupling constants such that only one free
parameter is left. Finally, the transition form factor $C^A_6(Q^2)$ can be
predicted in terms of $G_P(Q^2)$, the mean-square axial radius $\langle
r^2_A\rangle$, and the mean-square axial nucleon-to-$\Delta$ transition radius
$\langle r^2_{AN\Delta}\rangle$.

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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
30
The categories of this paper are: q-alg
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The categories of this paper are: eess