Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiative resonance couplings in $\gamma\pi\to\pi\pi$   Studies of the reaction $\gamma\pi\to\pi\pi$, in the context of the ongoing
Primakoff program of the COMPASS experiment at CERN, give access to the
radiative couplings of the $\rho(770)$ and $\rho_3(1690)$ resonances. We
provide a vector-meson-dominance estimate of the respective radiative width of
the $\rho_3$, $\Gamma_{\rho_3\to\pi\gamma}=48(18)$ keV, as well as its impact
on the $F$-wave in $\gamma\pi\to\pi\pi$. For the $\rho(770)$, we establish the
formalism necessary to extract its radiative coupling directly from the residue
of the resonance pole by analytic continuation of the $\gamma\pi\to\pi\pi$
amplitude to the second Riemann sheet, without any reference to the
vector-meson-dominance hypothesis.

1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph