Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-energy photon-photon fusion into three pions in Generalized Chiral
  Perturbation Theory   The processes $\gamma\gamma\to\pi^0\pi^0\pi^0$ and $\gamma\gamma\to \pi^+
\pi^- \pi^0$ are considered in Generalized Chiral Perturbation theory, in view
of their potential sensitivity to the mechanism of spontaneous breaking of
chiral symmetry and to various counterterms. The amplitudes are computed up to
order ${\cal O}(p^6)$. The event production rates are estimated for the Daphne
$\phi$-Factory and for a future $\tau$-Charm Factory.

31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an